Products HomeNIR Free-Space Isolators (690 - 1080 nm)
- Center Wavelengths from 730 to 1050 nm
- Isolation up to 60 dB
- Power Densities up to 500 W/cm²
- Custom Isolators Available Upon Request
IOT-5-850-MP
IO-3D-780-VLP
In Saddle
Removed
from Saddle
IO-5-940-HP
IO-D-780-VLP
IO-5-850-HP
Shown in the Saddle (SM1RC) Mounted on
an Optical Table Using a BA1 Base with an
SD1 1/4"-20 to 8-32 Counterbore Adapter
Please Wait
Click to Enlarge
Our Adjustable Narrowband Isolators can be tuned to maximize the peak isolation for any wavelength within a narrow spectral range (shaded in this graph). See the Wavelength Tuning tab for more details.
Click to Enlarge
Isolator in Custom Package for FiberBench Systems
Features
- Minimize Feedback into Optical Systems
- Free-Space Input and Output Ports
- Fixed or Tunable Wavelength Ranges
- Isolation at Center Wavelength from 34 to 60 dB
- Max Beam Diameter up to 4.7 mm
- Polarization-Dependent Input
Thorlabs is pleased to stock a variety of free-space optical isolators designed for use in the near infrared spectral range (690 - 1080 nm). Optical isolators, also known as Faraday isolators, are magneto-optic devices that preferentially transmit light along a single direction, shielding upstream optics from back reflections. Back reflections can create a number of instabilities in light sources, including intensity noise, frequency shifts, mode hopping, and loss of mode lock. In addition, intense back-reflected light can permanently damage optics. Please see the Isolator Tutorial tab for an explanation of the operating principles of a Faraday isolator.
In the near infrared wavelength range, we offer three types of isolators. The first type, Fixed Narrowband Isolators, contains fixed, factory-aligned optics, for which peak isolation and peak transmission occurs at a pre-defined center wavelength. Any deviation from this wavelength will cause a dip in isolation and transmission. The second type, Adjustable Narrowband Isolators, offers the user the ability to adjust the alignment of the input and output polarizers, allowing tuning of the center wavelength within a 30 - 40 nm range; see the tables below for details. The third type, Tandem Adjustable Narrowband Isolators, consists of two Faraday rotators in series, boosting the isolation to at least 55 dB at the expense of lower transmission. Please see the Isolator Types tab for additional design details and representative graphs of the wavelength-dependent isolation.
| Selection Guide for Isolators (Click Here for Our Full Selection) |
||
|---|---|---|
| Free-Space Isolators | ||
| Spectral Region | Wavelength Range | |
| UV | 365 - 385 nm | |
| Visible | 390 - 700 nm | |
| NIR | 690 - 1080 nm | |
| Nd:YAG | 1064 nm | |
| IR | 1110 - 2100 nm | |
| MIR | 2.20 - 9.80 µm | |
| Broadband Free-Space Isolators | ||
| Fiber Isolators | ||
| Custom Isolators | ||
The housing of each isolator shown here, except for the IO-D-780-VLP, is marked with an arrow that indicates the direction of forward propagation. The input and output apertures of the IO-D-780-VLP are indicated by the black and gold coloring of the cylinder, respectively. All isolators shown here (including the IO-D-780-VLP) have engravings that indicate the alignment of the input and output polarizers.
Thorlabs also manufactures isolators for fiber optic systems and wavelengths from the visible to the infrared (see the Selection Guide table to the left). As indicated in the tables below and pictured to the right, many of our stock isolators can also be provided in a mount designed for our FiberBench systems. If Thorlabs does not stock an isolator suited for your application, please refer to the Custom Isolators tab for information on our build-to-order options, or contact Tech Support. Thorlabs' in-house manufacturing service has over 25 years of experience and can deliver a free-space isolator tuned to your center wavelength from 244 nm to 4.55 µm. Our vertically integrated manufacturing structure allows us to offer faraday rotators used in optical isolators. We offer a selection of faraday rotators from stock and can provide custom faraday rotators upon request.
Shaded regions on a graph represent the center wavelength tuning range of the isolator. With these isolators, the isolation and transmission curves will shift as the center wavelength shifts. If the graph is not shaded, then the isolator is non-tunable. Please note that these curves were made from theoretical data and that isolation and transmission will vary from unit to unit.
Tuning an Adjustable Narrowband Isolator
- Optimize Our Isolators to Provide the Same Peak Isolation Anywhere Within Their Tuning Range
- Simple Tuning Procedure, Illustrated Below, Consists Primarily of Rotating the Output Polarizer
- Slight Transmission Losses Occur Due to Polarizer Rotation
Click to Enlarge
When the isolator is tuned away from its design wavelength, the maximum transmission falls because the output polarizer's transmission axis is not parallel to the polarization direction of the output light.
Click to Enlarge
Our Adjustable Narrowband Isolators can be tuned to maximize the peak isolation for any wavelength within a narrow spectral range (shaded in this graph).
Click for Details
Light Not at the Design Wavelength is Partially Transmitted
Click for Details
Light at the Design Wavelength is Rejected
Operating Principles of Optical Isolators
Thorlabs' Adjustable Narrowband Isolators are designed to provide the same peak isolation anywhere within a 30 - 40 nm tuning range. They contain a Faraday rotator that has been factory tuned to rotate light of the design wavelength by 45°. Light propagating through the isolator in the backward direction is polarized at 45° by the output polarizer and is rotated by 45° by the Faraday rotator, giving a net polarization of 90° relative to the transmission axis of the input polarizer. Therefore, an isolator rejects backward propagating light. See the Isolator Tutorial tab for a schematic of the beam path.
The magnitude of the rotation caused by the Faraday rotator is wavelength dependent. This means that light with a different wavelength than the design wavelength will not be rotated at exactly 45°. For example, if 980 nm light is rotated by 45° (that is, 980 nm is the design wavelength), then 975 nm light is rotated by 45.6°. If 975 nm light is sent backward through an isolator designed for 980 nm without any tweaking, it will have a net polarization of 45° + 45.6° = 90.6° relative to the axis of the input polarizer. The polarization component of the light parallel to the input polarizer's axis will be transmitted, and the isolation will therefore be significantly reduced.
Since the net polarization needs to be 90° to obtain high isolation, the output polarizer is rotated to compensate for the extra rotation being caused by the Faraday isolator. In our example, the new polarizer angle is 90° - 45.6° = 44.4°. This adjustment increases the isolation back to the same value as at the design wavelength.
Consequences of Wavelength Tuning Procedure
As a direct consequence of rotating the output polarizer, the maximum transmission in the forward direction decreases. 975 nm light propagating in the forward direction is polarized at 0° by the input polarizer and rotated by 45.6° by the Faraday rotator, but the output polarizer is now at 44.4°. The amount of the transmission decrease can be quantified using Malus' Law:
Malus' Law
Here, θ is the angle between the polarization direction of the light after the Faraday rotator and the transmission axis of the polarizer, I0 is the incident intensity, and I is the transmitted intensity. For small deviations from the center wavelength, the decrease in transmission is very slight, but for larger deviations, the decrease becomes noticeable. In our example (a 5 nm difference between the design wavelength and the usage wavelength), θ = 45.6° - 44.4° = 1.2°, so I = 0.9996 I0. This case is shown in the graphs above.
In applications, the decrease in transmission caused by the tuning procedure is usually less important than the significantly enhanced isolation gained by tuning. In fact, if the 980 nm isolator shown in the graphs above were used at 965 nm without tuning, the transmission difference would be negligible, but the isolation would be only 29 dB (instead of 36 dB). This case is also shown in the graphs above.
Thorlabs' isolator housings make it easy to rotate the output polarizer without disturbing the rest of the isolator. Our custom isolator manufacturing service (see the Custom Isolators tab) can also provide an isolator specifically designed for a particular center wavelength, which can eliminate or strongly mitigate the transmission losses that occur at the edges of the tuning range. These custom isolators are provided at the same cost as their equivalent stock counterparts. For more information, please contact Technical Support.
Illustrated Tuning Procedure
To optimize the isolation curve for a specific wavelength within the tuning range, the alignment of the output polarizer may be tweaked following the simple procedure outlined below. Only a minor adjustment is necessary to cover a range of several nanometers. The procedure differs slightly for different isolator packages, but the principle remains the same across our entire isolator family, and complete model-specific tuning instructions ship with each isolator.
Step 1:
Orient the isolator in the backward direction with respect to the beam (i.e., with the arrow pointing antiparallel to the beam propagation direction). A power meter with high sensitivity at low power levels should be placed after the isolator.
Use the included 5/64" hex key to loosen the isolator from its saddle.
Step 2:
Grip the isolator by the sides and gently bring it out of its saddle. It is only necessary to bring it out far enough to expose the 8-32 setscrew at the top, as shown in the photo to the left.
Step 3:
Use the included 5/64" hex key to tighten the isolator back into its saddle with the 8-32 setscrew exposed.
The isolator is mechanically stable in this position as long as the isolator has not been brought forward too much. (The amount shown in the image to the left is safe by several millimeters.) It should therefore not be necessary to reinsert the isolator at the end of the tuning procedure.
Step 4:
Loosen the exposed 8-32 setscrew using the included 5/64" hex key. At this point, the output polarizer will be free to rotate.
Step 5:
Rotate the output polarizer to minimize the power on the power meter. As explained above, the necessary adjustment should be only a few degrees, depending upon the desired center wavelength. Tighten the 8-32 setscrew once optimization is achieved.
As long as the isolator was not brought forward too much at the end of Step 2, the isolator will be mechanically stable in this position. Attempting to reinsert the isolator at this point may cause misalignment.
Fixed Narrowband Isolator
The isolator is set for 45° of rotation at the design wavelength. The polarizers are non-adjustable and are set to provide maximum isolation at the design wavelength. As the wavelength changes the isolation will drop; the graph shows a representative profile.
- Fixed Rotator Element, Fixed Polarizers
- Polarization Dependent
- Smallest and Least Expensive Isolator Type
- No Tuning
Adjustable Narrowband Isolator
The isolator is set for 45° of rotation at the design wavelength. If the usage wavelength changes, the Faraday rotation will change, thereby decreasing the isolation. To regain maximum isolation, the output polarizer can be rotated to "re-center" the isolation curve. This rotation causes transmission losses in the forward direction that increase as the difference between the usage wavelength and the design wavelength grows.
- Fixed Rotator Element, Adjustable Polarizers
- Polarization Dependent
- General-Purpose Isolator
Adjustable Broadband Isolator
The isolator is set for 45° of rotation at the design wavelength. There is a tuning ring on the isolator that adjusts the amount of Faraday rotator material that is inserted into the internal magnet. As your usage wavelength changes, the Faraday rotation will change, thereby decreasing the isolation. To regain maximum isolation, the tuning ring is adjusted to produce the 45° of rotation necessary for maximum isolation.
- Adjustable Rotator Element, Fixed Polarizers
- Polarization Dependent
- Simple Tuning Procedure
- Broader Tuning Range than Adjustable Narrowband Isolators
Fixed Broadband Isolator
A 45° Faraday rotator is coupled with a 45° crystal quartz rotator to produce a combined 90° rotation on the output. The wavelength dependences of the two rotator materials work together to produce a flat-top isolation profile. The isolator does not require any tuning or adjustment for operation within the designated design bandwidth.
- Fixed Rotator Element, Fixed Polarizers
- Polarization Dependent
- Largest Isolation Bandwidth
- No Tuning Required
Tandem Isolators
Tandem isolators consist of two Faraday rotators in series, which share one central polarizer. Since the two rotators cancel each other, the net rotation at the output is 0°. Our tandem designs yield narrowband isolators that may be fixed or adjustable.
- Up to 60 dB Isolation
- Polarization Dependent
- Highest Isolation
- Fixed or Adjustable
Polarizer Types, Sizes, and Power Limits
Thorlabs designs and manufactures several types of polarizers that are used across our family of optical isolators. Their design characteristics are detailed below. The part number of given isolator has an identifier for the type of polarizer that isolator contains. For more details on how the part number describes each isolator, see the given isolator's manual.
| Polarizer Comparison | |||
|---|---|---|---|
| Type | Schematic (Click to Enlarge) |
Maximum Power Density | Description |
| Very Low Power (C) |
 |
10 W/cm2 (CW, Blocking) 25 W/cm2 (CW, Transmission) |
Our Very Low Power Absorptive Film Polarizers are compact options for isolating free-space beams. For light polarized perpendicular to the polarizer's transmission axis, the max power density is 10 W/cm2, while for light polarized parallel to the polarizer's transmission axis, the max power density is 25 W/cm2. |
| Very Low Power (VLP) |
|
25 W/cm2 (CW, Blocking) 100 W/cm2 (CW, Transmission) |
These polarizers are also for use with very low power sources but are made with a different material than the type C polarizers listed above. This gives these polarizers a higher maximum power density. For light polarized perpendicular to the polarizer's transmission axis, the max power density is 25 W/cm2, while for light polarized parallel to the polarizer's transmission axis, the max power density is 100 W/cm2. |
| Wire Grid (W) |
|
25 W/cm2 (CW) | Wire Grid Polarizers are used in our mid-IR isolators. They consist of a linearly spaced wire grid pattern that is deposited onto an AR-coated silicon substrate. |
| Polarizing Beamsplitter (PBS) |
 |
13 - 50 W/cm2 (CW) | Polarizing Beamsplitter Cubes are commonly used in low-power applications and feature an escape window useful for monitoring or injection locking. |
| α-BBO Glan-Laser (GLB) |
 |
100 W/cm2 (CW) | Thorlabs' α-BBO Glan-Laser polarizers are all based on high-grade, birefringent, α-BBO crystals with a wavelength range of 210 - 450 nm. Due to the birefringent structure of α-BBO, a phase delay is created between two orthogonally polarized waves traveling in the crystal. These are similar to the High Power (HP) polarizers, but have a different escape angle. |
| Low Power (LP) |
 |
250 W/cm2 (CW) 25 MW/cm2 (Pulsed) |
Our Low Power Polarizers are Glan-type, crystal polarizers, providing high transmission and power densities at the expense of a larger package than Very Low Power (VLP) and Polarizing Beamsplitter (PBS) polarizers. |
| Medium Power (MP) |
 |
100 W/cm2 (CW) 50 MW/cm2 (Pulsed) |
Medium Power Polarizers are Glan-type, crystal polarizers, capable of handling higher powers. The rejected beam is internally scattered, which reduces the maximum power density, but also eliminates a stray beam from the setup. |
| High Power (HP) |
|
500 W/cm2 (CW) 150 MW/cm2 (Pulsed) |
High Power Polarizers are Glan-type, crystal polarizers, similar in size and transmission to Medium Power (MP) polarizers, but capable of handling higher powers. They feature an escape window suited for injection locking. |
| Yttrium Orthovanadate (YV) |
|
25 W/cm2 (CW) | YV polarizers are similar to the Medium Power (MP) Glan-type crystal polarizers; however, by using yttrium orthovanadate (YVO4) rather than calcite, YV polarizers can accommodate wavelengths in the 2.0 - 3.4 µm range. The rejected beam is internally scattered, which reduces the maximum power density, but also eliminates a stray beam from the setup. |
| Very High Power (VHP) |
 |
20 kW/cm2 (CW) 2 GW/cm2 (Pulsed) |
Our Very High Power Polarizers are based on Brewster windows and feature the highest power handling possible. These polarizers have larger packages than HP-based designs, but are also more economical. All VHP-based designs also feature escape windows. |
Optical Isolator Tutorial
Function
An optical isolator is a passive magneto-optic device that only allows light to travel in one direction. Isolators are used to protect a source from back reflections or signals that may occur after the isolator. Back reflections can damage a laser source or cause it to mode hop, amplitude modulate, or frequency shift. In high-power applications, back reflections can cause instabilities and power spikes.
An isolator's function is based on the Faraday Effect. In 1842, Michael Faraday discovered that the plane of polarized light rotates while transmitting through glass (or other materials) that is exposed to a magnetic field. The direction of rotation is dependent on the direction of the magnetic field and not on the direction of light propagation; thus, the rotation is non-reciprocal. The amount of rotation β equals V x B x d, where V, B, and d are as defined below.
Figure 1. Faraday Rotator's Effect on Linearly Polarized Light
Faraday Rotation
β = V x B x d
V: the Verdet Constant, a property of the optical material, in radians/T • m.
B: the magnetic flux density in teslas.
d: the path length through the optical material in meters.
An optical isolator consists of an input polarizer, a Faraday rotator with magnet, and an output polarizer. The input polarizer works as a filter to allow only linearly polarized light into the Faraday rotator. The Faraday element rotates the input light's polarization by 45°, after which it exits through another linear polarizer. The output light is now rotated by 45° with respect to the input signal. In the reverse direction, the Faraday rotator continues to rotate the light's polarization in the same direction that it did in the forward direction so that the polarization of the light is now rotated 90° with respect to the input signal. This light's polarization is now perpendicular to the transmission axis of the input polarizer, and as a result, the energy is either reflected or absorbed depending on the type of polarizer.
Figure 2. A single-stage, polarization-dependent isolator. Light propagating in the reverse direction is rejected by the input polarizer.
Polarization-Dependent Isolators
The Forward Mode
In this example, we will assume that the input polarizer's axis is vertical (0° in Figure 2). Laser light, either polarized or unpolarized, enters the input polarizer and becomes vertically polarized. The Faraday rotator will rotate the plane of polarization (POP) by 45° in the positive direction. Finally, the light exits through the output polarizer which has its axis at 45°. Therefore, the light leaves the isolator with a POP of 45°.
In a dual-stage isolator, the light exiting the output polarizer is sent through a second Faraday rotator followed by an additional polarizer in order to achieve greater isolation than a single-stage isolator.
The Reverse Mode
Light traveling backwards through the isolator will first enter the output polarizer, which polarizes the light at 45° with respect to the input polarizer. It then passes through the Faraday rotator rod, and the POP is rotated another 45° in the positive direction. This results in a net rotation of 90° with respect to the input polarizer, and thus, the POP is now perpendicular to the transmission axis of the input polarizer. Hence, the light will either be reflected or absorbed.
Click for DetailsFigure 3. A single-stage, polarization-independent isolator. Light is deflected away from the input path and stopped by the housing.
Polarization-Independent Fiber Isolators
The Forward Mode
In a polarization independent fiber isolator, the incoming light is split into two branches by a birefringent crystal (see Figure 3). A Faraday rotator and a half-wave plate rotate the polarization of each branch before they encounter a second birefringent crystal aligned to recombine the two beams.
In a dual-stage isolator, the light then travels through an additional Faraday rotator, half-wave plate, and birefringent beam displacer before reaching the output collimating lens. This achieves greater isolation than the single-stage design.
The Reverse Mode
Back-reflected light will encounter the second birefringent crystal and be split into two beams with their polarizations aligned with the forward mode light. The faraday rotator is a non-reciprocal rotator, so it will cancel out the rotation introduced by the half wave plate for the reverse mode light. When the light encounters the input birefringent beam displacer, it will be deflected away from the collimating lens and into the walls of the isolator housing, preventing the reverse mode from entering the input fiber.
General Information
Damage Threshold
With 25 years of experience and 5 U.S. patents, our isolators typically have higher transmission and isolation than other isolators, and are smaller than other units of equivalent aperture. For visible to YAG laser Isolators, Thorlabs' Faraday Rotator crystal of choice is TGG (terbium-gallium-garnet), which is unsurpassed in terms of optical quality, Verdet constant, and resistance to high laser power. Thorlabs' TGG Isolator rods have been damage tested to 22.5 J/cm2 at 1064 nm in 15 ns pulses (1.5 GW/cm2), and to 20 kW/cm2 CW. However, Thorlabs does not bear responsibility for laser power damage that is attributed to hot spots in the beam.
Figure 4. Pulse Dispersion Measurements Before and After an IO-5-780-HP Isolator
Magnet
The magnet is a major factor in determining the size and performance of an isolator. The ultimate size of the magnet is not simply determined by magnetic field strength but is also influenced by the mechanical design. Many Thorlabs magnets are not simple one piece magnets but are complex assemblies. Thorlabs' modeling systems allow optimization of the many parameters that affect size, optical path length, total rotation, and field uniformity. Thorlabs' US Patent 4,856,878 describes one such design that is used in several of the larger aperture isolators for YAG lasers. Thorlabs emphasizes that a powerful magnetic field exists around these Isolators, and thus, steel or magnetic objects should not be brought closer than 5 cm.
Temperature
The magnets and the Faraday rotator materials both exhibit a temperature dependence. Both the magnetic field strength and the Verdet Constant decrease with increased temperature. For operation greater than ±10 °C beyond room temperature, please contact Technical Support.
Pulse Dispersion
Pulse broadening occurs anytime a pulse propagates through a material with an index of refraction greater than 1. This dispersion increases inversely with the pulse width and therefore can become significant in ultrafast lasers.
τ: Pulse Width Before Isolator
τ(z): Pulse Width After Isolator
Example:
t = 197 fs results in t(z) = 306 fs (pictured to the right)
t = 120 fs results in t(z) = 186 fs
Click to Enlarge
Custom Isolator Example
Custom Adjustable Narrowband Isolator with Different Input and Output Polarizers Optimized for 650 nm Wavelength and 40 °C Temperature.
OEM Application Services
- Direct Integration to Laser Head Assemblies
- Combination Isolator and Fiber Coupling Units
- Minimum Footprint Packages
- Filter Integration
- Active Temperature Control and Monitoring
- Feedback Monitoring
- Environmental Qualification
- Private Labeling
- ITAR-Compliant Assembly
OEM and Non-Standard Isolators
In an effort to provide the best possible service to our customers, Thorlabs has made a commitment to ship our most popular free-space and fiber isolator models from stock. We currently offer same-day shipping on more than 90 isolator models. In addition to these stock models, non-stock isolators with differing aperture sizes, wavelength ranges, package sizes, and polarizers are available. In addition, we can create isolators tuned for specific operating temperatures and isolators that incorporate thermistors with heating or cooling elements for active temperature control and monitoring. These generally have the same price as a similar stock unit. If you would like a quote on a non-stock isolator, please fill out the form below and a member of our staff will be in contact with you.
Thorlabs has many years of experience working with OEM, government, and research customers, allowing us to tailor your isolator to specific design requirements. In addition to customizing our isolators (see the OEM Application Services list to the right), we also offer various application services.
| Parameter | Range |
|---|---|
| Wavelength Range | From 244 - 4550 nma |
| Aperture Sizes | Up to Ø15 mm |
| Polarization Dependence | Dependent or Independent |
| Max Powerb | Up to 2 GW/cm² |
| Isolation | Up to 60 dB (Tandem Units) |
| Operating Temperature | 10 - 70 °C |
Free-Space Isolators
We are able to provide a wide range of flexibility in manufacturing non-stock, free-space isolators. Almost any selection of specifications from our standard product line can be combined to suit a particular need. The table to the right shows the range of specifications that we can meet.
We offer isolators suitable for both narrowband and broadband applications. The size of the housing is very dependent on the desired maximum power and aperture size, so please include a note in the quote form below if you have special requirements.
Faraday Rotators
We offer Faraday rotators center wavelengths from 532 nm to 1550 nm. These are the same components used to make our isolators and rotate the polarization of incoming light by 45°. Please contact Tech Support if you require a faraday rotator with a rotation angle or center wavelength outside of the aforementioned specifications.
| Parameter | Range |
|---|---|
| Wavelength Range | From 633 - 2050 nma |
| Polarization Dependence | Dependent or Independent |
| Max Powerb (Fiber to Free-Space) | 30 W |
| Max Powerb (Fiber to Fiber) | 20 W |
| Operating Temperature | 10 - 70 °C |
Fiber Isolators
Thorlabs is uniquely positioned to draw on experience in classical optics, fiber coupling, and isolators to provide flexible designs for a wide range of fiber optic specifications. Current design efforts are focused on increasing the Maximum power of our fiber isolators at and near the 1064 nm wavelength. We offer models with integrated ASE filters and taps. The table to the right highlights the range of specifications that we can meet.
The fiber used is often the limiting factor in determining the Maximum power the isolator can handle. We have experience working with single mode (SM) and polarization-maintaining fibers (PM); single-, double- and triple-clad fibers; and specialty fibers like 10-to-30 µm LMA fibers and PM LMA fibers. For more information about the fiber options available with our custom isolators, please see the expandable tables below.
In the spectral region below 633 nm, we recommend mounting one of our free-space isolators in a FiberBench system. A FiberBench system consists of pre-designed modules that make it easy to use free-space optical elements with a fiber optic system while maintaining excellent coupling efficiency. Upon request, we can provide select stock isolators in an optic mount with twin steel dowel pins for our FiberBench systems, as shown to the left.
We are also in the process of extending our fiber isolator capabilities down into the visible region. For more information, please contact Technical Support.
Custom Fiber Isolator
Custom Free-Space Isolator for Wavelengths Below 633 nm
Click to Enlarge
Twin Steel Pins Insert into FiberBench
Click to Enlarge
Mounted Isolator
| Polarization Independent Fiber |
|---|
| Polarization Maintaining Fiber |
|---|
Make to Order Options
The expandable tables below provide information on some common isolator and rotator specials we have manufactured in the past. We keep the majority of the components for these custom isolators in stock to ensure quick builds, so these specials are available with an average lead time of only 2-4 weeks. Please use the Non-Stock Isolator Worksheet below for a quote.
| Adjustable Narrowband Isolators |
|---|
| Faraday Rotators |
|---|
| Fixed Narrowband Isolators |
|---|
| Fixed Broadband Isolators |
|---|
Custom Request Form
Request a custom isolator quote using the form below or by contacting us for more information at (973) 300-3000.
| Posted Comments: | |
Bryan Hennelly
(posted 2019-12-11 16:11:10.643) I am wondering if I buy two optical isolators with 30db and place in series, will this provide isolation of 60db? YLohia
(posted 2019-12-12 04:46:15.0) Hello, thank you for contacting Thorlabs. Yes, stacking the isolators will add up the total isolation. This is similar to how our Tandem Isolators work. Tandem isolators consist of two Faraday rotators in series, which share one central polarizer. Since the two rotators cancel each other, the net rotation at the output is 0°. yongqi.shi
(posted 2019-01-29 15:07:01.443) Dear Sir/Madam, the isolator I'm using now cannot reach the nominal 92% of transmission. I have maximised the rotation angle of both polarisers. The maximum transmission is 82%. What would be the reason? The beam size is somehow within the aperture and it is nearly pure linear polarised light. Thank you for your explanation in advance. nbayconich
(posted 2019-02-06 10:28:43.0) Thank you for contacting Thorlabs. Can you provide the operating wavelength of your source and the approximate beam size? Our 4.7mm maximum beam size is defined as containing 100% of the beam energy. If you are measuring the beam diameter based on the 1/e^2 diameter your beam could be clipping.
Is the output polarizer aligned 45 degrees relative to the input polarizer of the isolator assuming the source is 780nm?
A tech support representative will reach out to you directly to help troubleshoot this problem you are seeing. mshramenko
(posted 2018-07-18 15:42:45.603) I have an 830-nm polarization-dependent isolator (IO-3D-830-VLP) and I am planning to use it in an experimental setup at different temperatures. Could you please tell me what the operating temperature range is for this type of isolators? Thank you. Michael. YLohia
(posted 2018-07-19 09:47:27.0) Hello, thank you for contacting Thorlabs. I have reached out to you directly with the temperature dependence data we have. One thing to note is that condensation could be an issue when working below room temperature and we really do not recommend going below 10 C. chenav
(posted 2017-05-07 21:08:55.907) Working around these isolators with standard screwdrivers is very difficult because they are magnetic and strongly pulled towards the isolator body, and often hit it with great power. SAD. How about a line of non-magnetic screwdrivers for this kind of application (both large for table bolts and small for the isolator setscrews)? tcampbell
(posted 2017-05-08 10:39:26.0) Response from Tim at Thorlabs: thank you for your feedback. We recently released a line of non-magnetic hex keys, which can be found here: www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=1407#11029 chenav
(posted 2016-11-16 14:48:13.073) This isolator (and others) feature two small screws which tighten the input and output polarizers. Aligning the isolator requires loosening these screws, but unfortunately they are typically situated on opposite sides of the isolator body which means it cannot be oriented such that they are both accessibly e.g. from the top. As a result one has to orient the isolator such that these screws are to the sides (left and right) of it, and this makes accessing them very hard. This seems like an easy problem to fix. tfrisch
(posted 2016-11-22 09:49:34.0) Hello, thank you for contacting Thorlabs. I understand that screw orientation can be critical in applications where space is limited. I've passed these notes on to our design team. Thorlabs
(posted 2010-11-04 14:23:45.0) Response from Javier at Thorlabs to rshewmon: Thank you very much for your feedback. We are currently working on revamping the design of many of the components used in our freespace isolators. Your input will be integrated into the design plan of these parts. I will keep you updated of the status of this project. rshewmon
(posted 2010-11-04 12:41:30.0) We use a handful of these isolators, they work pretty well but theres one complaint: does the input port really need to be shiny? If the beam going into the isolator gets a little bit misaligned, it can get reflected back to the source. Some competing brands (like Linos) have anodized aluminum around the input aperture. |
The following selection guide contains all of Thorlabs' Free-Space Optical Isolators. Click the colored bars below to to see specifications and options for each wavelength range and isolator type. Please note that Thorlabs also offers fiber optical isolators and custom optical isolators.
IO-5-730-HP Simplified Mechanical Drawing
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| Item # | IO-5-730-HPa |
| Type | Adjustable Narrowband |
| Center Wavelength | 730 nm |
| Tuning Range | 710 - 750 nm |
| Operating Range | 690 - 770 nm |
| Transmission | 90% |
| Isolation | ≥38 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diameterb | 4.7 mm |
| Max Powerc | 35 W |
| Max Power Density | 500 W/cm2 |
| Compatible Mounting Adaptersd | CP36 SM1RCe (SM1RC/M) SM1TC SM2A21 |
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| Item # | IO-D-780-VLPa,b | IO-3D-780-VLPb | IO-3-780-HPc | IO-5-780-VLP | IOT-5-780-VLP | IOT-5-780-MP | IO-5-780-HPc |
| Type | Fixed Narrowband | Fixed Narrowband | Adjustable Narrowband | Adjustable Narrowband | Tandem Adjustable Narrowband | Tandem Adjustable Narrowband | Adjustable Narrowband |
| Center Wavelength | 780 nm | 780 nm | 780 nm | 780 nm | 780 nm | 780 nm | 780 nm |
| Tuning Range | N/A | N/A | 760 - 800 nm | 760 - 800 nm | 760 - 800 nm | 760 - 800 nm | 760 - 800 nm |
| Operating Range | 770 - 790 nm | 760 - 800 nm | 740 - 820 nm | 740 - 820 nm | 740 - 820 nm | 740 - 820 nm | 740 - 820 nm |
| Transmission | 48 - 55% | 86% | 92% | 85% | 80% | 80% | 92% |
| Isolation | 36 - 40 dB | 34 - 40 dB | 34 - 40 dB | 35 dB (Min) | 55 dB (Min) | 60 dB (Min) | 38 - 44 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diameterd | 1.6 mm | 2.7 mm | 2.7 mm | 4.7 mm | 4.7 mm | 4.7 mm | 4.7 mm |
| Max Powere | 0.2 W | 0.7 W | 15 W | 1.7 W | 1.7 W | 7.0 W | 40 W |
| Max Power Density | 25 W/cm2 | Blocking:f 25 W/cm2 Transmission:f 100 W/cm2 |
500 W/cm2 | Blocking:f 25 W/cm2 Transmission:f 100 W/cm2 |
Blocking:f 25 W/cm2 Transmission:f 100 W/cm2 |
100 W/cm2 | 500 W/cm2 |
| Compatible Mounting Adaptersg | N/A | H1C SM1B2 SM087RCh (SM087RC/M) |
CP36 SM1RCi (SM1RC/M) SM1TC SM2A21 |
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| Item # | IO-3D-830-VLPa | IO-3D-850-VLPa | IO-3-850-HPb | IO-5-850-VLP | IOT-5-850-VLP | IOT-5-850-MP | IO-5-850-HPb |
| Type | Fixed Narrowband | Fixed Narrowband | Adjustable Narrowband | Adjustable Narrowband | Tandem Adjustable Narrowband | Tandem Adjustable Narrowband | Adjustable Narrowband |
| Center Wavelength |
830 nm | 850 nm | 850 nm | 850 nm | 850 nm | 850 nm | 850 nm |
| Tuning Range | N/A | N/A | 835 - 865 nm | 830 - 870 nm | 830 - 870 nm | 830 - 870 nm | 835 - 865 nm |
| Operating Range | 810 - 850 nm | 830 - 870 nm | 810 - 890 nm | 810 - 890 nm | 820 - 890 nm | 810 - 890 nm | 810 - 890 nm |
| Transmission | 86% | 86% | 92% | 88% | 80% | 80% | 92% |
| Isolation | 34 - 40 dB | 34 - 40 dB | 34 - 40 dB | 35 dB (Min) | 55 dB (Min) | 60 dB (Min) | 38 - 44 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diameterc | 2.7 mm | 2.7 mm | 2.7 mm | 4.7 mm | 4.7 mm | 4.7 mm | 4.7 mm |
| Max Powerd | 0.7 W | 0.7 W | 15 W | 1.7 W | 1.7 W | 7.0 W | 40 W |
| Max Power Density | Blocking:e 25 W/cm2 Transmission:e 100 W/cm2 |
Blocking:e 25 W/cm2 Transmission:e 100 W/cm2 |
500 W/cm2 | Blocking:e 25 W/cm2 Transmission:e 100 W/cm2 |
Blocking:e 25 W/cm2 Transmission:e 100 W/cm2 |
100 W/cm2 | 500 W/cm2 |
| Compatible Mounting Adaptersf | H1C SM1B2 SM087RCg (SM087RC/M) |
CP36 SM1RCh (SM1RC/M) SM1TC SM2A21 |
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IO-5-895-HP Simplified Mechanical Drawing
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| Item # | IO-5-895-HPa |
| Type | Adjustable Narrowband |
| Center Wavelength | 895 nm |
| Tuning Range | 875 - 915 nm |
| Operating Range | 855 - 935 nmb |
| Transmission | 90% |
| Isolation | 38 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diameterc | 4.7 mm |
| Max Powerd | 35 W |
| Max Power Density | 500 W/cm2 |
| Compatible Mounting Adapterse | CP36 SM1RCf (SM1RC/M) SM1TC SM2A21 |
IO-5-940-HP Simplified Mechanical Drawing
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| Item # | IO-5-940-HPa |
| Type | Adjustable Narrowband |
| Center Wavelength | 940 nm |
| Tuning Range | 920 - 960 nm |
| Operating Range | 900 - 980 nm |
| Transmission | 90% |
| Isolation | 38 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diameterb | 4.7 mm |
| Max Powerc | 35 W |
| Max Power Density | 500 W/cm2 |
| Compatible Mounting Adaptersd | CP36 SM1RCe (SM1RC/M) SM1TC SM2A21 |
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| Item # | IO-3D-980-VLPa | IO-5-980-VLP | IOT-5-980-VLPb | IO-5-980-HPc |
| Type | Fixed Narrowband | Adjustable Narrowband | Tandem Adjustable Narrowband | Adjustable Narrowband |
| Center Wavelength | 980 nm | 980 nm | 980 nm | 980 nm |
| Tuning Range | N/A | 960 - 1000 nm | 965 - 995 nm | 965 - 995 nm |
| Operating Range | 960 - 1000 nm | 940 - 1020 nm | 950 - 1010 nm | 950 - 1010 nm |
| Transmission | 90% | 90% | 80% | 93% |
| Isolation | 38 dB | 38 - 40 dB | 55 dB (Min) | 38 - 44 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diameterd | 2.7 mm | 4.7 mm | 4.7 mm | 4.7 mm |
| Max Powere | 0.7 W | 1.7 W | 1.7 W | 40 W |
| Max Power Density | Blocking:f 25 W/cm2 Transmission:f 100 W/cm2 |
Blocking:f 25 W/cm2 Transmission:f 100 W/cm2 |
Blocking:f 25 W/cm2 Transmission:f 100 W/cm2 |
500 W/cm2 |
| Compatible Mounting Adaptersg | H1C SM1B2 SM087RCh (SM087RC/M) |
CP36 SM1RCi (SM1RC/M) SM1TC SM2A21 |
CP37 (CP37/M) SM30RC (SM30RC/M) |
CP36 SM1RCi (SM1RC/M) SM1TC SM2A21 |
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| Item # | IO-3D-1030-VLPa | IO-5-1030-VLPb | IO-5-1030-HPb,c |
| Type | Fixed Narrowband | Adjustable Narrowband | Adjustable Narrowband |
| Center Wavelength | 1030 nm | 1030 nm | 1030 nm |
| Tuning Range | N/A | 1010 - 1050 nm | 1010 - 1050 nm |
| Operating Range | 1010 - 1050 nm | 990 - 1070 nmd | 1000 - 1060 nmd |
| Transmission | 90% | 90% | 93% |
| Isolation | 38 - 44 dB | 35 - 40 dB | 38 - 44 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diametere | 2.7 mm | 4.7 mm | 4.7 mm |
| Max Powerf | 700 mW | 1.7 W | 40 W |
| Max Power Density | Blocking:g 25 W/cm2 Transmission:g 100 W/cm2 |
Blocking:g 25 W/cm2 Transmission:g 100 W/cm2 |
500 W/cm2 |
| Compatible Mounting Adaptersh | CP36 SM1RCi (SM1RC/M) SM1TC SM2A21 |
SM3B2 C2RC (C2RC/M) |
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| Item # | IO-3D-1050-VLPa | IO-5-1050-HPb,c |
| Type | Fixed Narrowband | Adjustable Narrowband |
| Center Wavelength | 1050 nm | 1050 nm |
| Tuning Range | N/A | 1030 - 1070 nm |
| Operating Range | 1030 - 1070 nmd | 1020 - 1080 nmd |
| Transmission | 90% | 93% |
| Isolation | 38 - 44 dB | 38 - 44 dB |
| Performance Graph (Click for Details) |
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| Max Beam Diametere | 2.7 mm | 4.7 mm |
| Max Powerf | 700 mW | 40 W |
| Max Power Density | Blocking:g 25 W/cm2 Transmission:g 100 W/cm2 |
500 W/cm2 |
| Compatible Mounting Adaptersh | CP36 SM1RCi (SM1RC/M) SM1TC SM2A21 |
SM3B2 C2RC (C2RC/M) |
These adapters provide mechanical compatibility between our isolator bodies and SM1 (1.035"-40) lens tubes, SM30 (M30.5-0.5) lens tubes, SM2 (2.035"-40) lens tubes, SM3 (3.035"-40) lens tubes, 30 mm cage systems, Ø1/2" posts, Ø1" posts, and our FiberBench systems.
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| Item # | H1C | SM1B2 | SM087RC(/M) | CP36 | SM1RC(/M) | SM1TC | SM2A21 |
| Isolator Diameter |
0.865" | 0.865" | 0.865" | 1.2" | 1.2" | 1.2" | 1.2" |
| Mounting Options |
FiberBench Systems | SM1 Lens Tubes | Ø1/2" Posts | 30 mm Cage Systems | Ø1/2" Posts | Ø1/2" Posts | SM2 Lens Tubes or Mechanics with Ø2" Bore |
| Compatible Isolators | IO-3D-780-VLP IO-3D-830-VLP IO-3D-850-VLP IO-3D-980-VLP |
IO-5-730-HP
IO-5-780-VLP IOT-5-780-VLP IOT-5-780-MP IO-3-780-HP IO-5-780-VLP IOT-5-780-VLP
IOT-5-850-VLP IOT-5-850-MP IO-3-850-HP IO-5-850-VLP IO-5-850-HP IO-5-895-HP
IO-5-940-HP IO-5-980-VLP IO-5-980-HP IO-3D-1030-VLP IO-3D-1050-VLP |
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| Item # | CP37(/M) | SM30RC(/M) | SM30TC | SM3B2 | C2RC(/M) |
| Isolator Diameter |
1.38" | 1.38" | 1.38" | 2.0" | 2.0" |
| Mounting Options |
30 mm Cage Systems and Ø1/2" Posts |
Ø1/2" Posts | Ø1/2" Posts | SM3 Lens Tubes | Ø1/2" Posts or Ø1" Posts |
| Compatible Isolators | IOT-5-980-VLP | IO-5-1030-VLP IO-5-1030-HP IO-5-1050-HP |
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The SM3B2 will be retired without replacement when stock is depleted. If you require this part for line production, please contact our OEM Team.
NIR Free-Space Isolators