UV Fused Silica Broadband Plate Beamsplitters (Coating: 700 - 1100 nm)


  • Beamsplitter Coating for 700 - 1100 nm at 45° Incidence
  • 10:90, 30:70, 50:50, 70:30, or 90:10 Split Ratio
  • Ø1/2", Ø1", 25 mm x 36 mm, and Ø2" Sizes

BSX17

Ø2"

BSS11

Ø1"

BSN05

Ø1/2"

BSW11R

25 mm x 36 mm

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Plate Beamsplitter Selection Guide
Substrate Beamsplitter Coating
UV Fused Silica 250 - 450 nm
350 - 1100 nm
400 - 700 nm
532 nm and 1064 nm
600 - 1700 nm
700 - 1100 nm
1.2 - 1.6 µm
IR Fused Silica 0.9 - 2.6 µm
Calcium Fluoride 1 - 6 μm
2 - 8 μm
Zinc Selenide 1 - 12 μm
7 - 14 μm

Features

  • Beamsplitter Coating on Front Surface: 700 - 1100 nm
  • Five Split Ratios Available (R:T) Optimized for a 45° Angle of Incidence (AOI)
    • 10:90
    • 30:70
    • 50:50
    • 70:30
    • 90:10
  • Antireflection (AR) Coating on Back Surface: 700 - 1100 nm
  • Ø1/2", Ø1", 25 mm x 36 mm, and Ø2" Versions Available
  • UV Fused Silica Substrate (Transmission Curve; Detailed Substrate information)
  • 30 arcmin Wedged Back Surface on Round Beamsplitters Minimizes Ghosting

Thorlabs' UV Fused Silica Broadband Beamsplitters provide split ratios of 10:90, 30:70, 50:50, 70:30, or 90:10 and have a dielectric beamsplitter coating optimized for the 700 – 1100 nm range deposited on the front surface. The dielectric coating is optimized for a 45° angle of incidence and provides long-term stability. These beamsplitters come in Ø1/2", Ø1", 25 mm x 36 mm, and Ø2" sizes.

These plate beamsplitters are fabricated from UV-grade fused silica, which offers high transmission deep into the UV, good homogeneity, and a lower coefficient of thermal expansion than N-BK7. In addition, UV fused silica exhibits virtually no laser-induced fluorescence (as measured at 193 nm), making it an ideal choice for applications from the UV to the near IR.

To help reduce unwanted interference effects (e.g., ghost images) caused by the interaction of light reflected from the front and back surfaces of the optic, all of these plate beamsplitters have an antireflection (AR) coating deposited onto the back surface. This coating is designed for the same operating wavelength range as the beamsplitter coating on the front surface. Approximately 4% of the light incident at 45° on an uncoated substrate will be reflected; by applying an AR coating to the back side of the beamsplitter, this percentage is reduced to an average of less than 1% over the entire operating range of the coating. In addition to this feature, the back of all of our round broadband plate beamsplitters has a 30 arcmin wedge; therefore, the fraction of light that does get reflected from this AR-coated surface will diverge.

The edge of each round plate beamsplitter is engraved with the item number and an arrow pointing to the AR-coated, wedged surface (see the Drawings tab in the blue info icons below for an illustration). Our rectangular beamsplitters, which have been designed for mounting in microscopy filter cubes, feature the engraved item number on the side with the beamsplitter coating, making it easy to differentiate between the front and back surfaces.

Thorlabs offers three types of non-polarizing beamsplitters: Non-polarizing Beamsplitting Cubes (mounted and unmounted), Pellicle Beamsplitters (mounted and unmounted), and the Plate Beamsplitters (see below and selection guide above). For a direct comparison of the performance of our non-polarizing beamsplitting cube, plate, and pellicle at 633 nm, see the Lab Facts tab.

Thorlabs Lab Fact: Beamsplitter Package Matters

We present laboratory measurements of the polarization angle, split ratio, and total throughput power of a beam transmitted through Thorlabs plate, cube, and pellicle beamsplitters. While all non-polarizing beamsplitters function similarly, the exact performance is different for different types of beamsplitter. Each type of beamsplitter contains its own advantages and disadvantages compared to other types of beamsplitters. Appropriate choice of beamsplitter is essential to sensitive experimental systems. We present a complete analysis and comparison of optical parameters for three common types of non-polarizing beamsplitters.

For our experiment we used the former generation HRS015 stabilized HeNe laser (replaced by the HRS015B) as the light source for our investigation. A linear polarizer is used to set the laser beam's polarization axis to 45° in order to provide equal S- and P-polarized light incident on the beamsplitter. The beamsplitter under investigation was then placed in the beampath, and its split beams directed to appropriate detectors. The total power though the optic, polarization states, split ratios, and angle of incidence effects were investigated under this configuration.

Lab Facts Complete Summary

The plots below summarize the measured results for all three types of beamsplitters. From these graphs the performance of each optic can be easily compared to one another. The bottom left plot summarizes the results for the total power throughput for each optic. The total power throughput is measured as the fraction of input power. While the plate and pellicle beamsplitters perform rather similarly, the cube shows signs of absorption inside the optic. Additionally, this plot shows the relative insensitivity of throughput power to angle of incidence. The bottom middle graph summarizes the results for the output polarization angle for each optic. The cube shows the most similar polarization angles between the reflected and transmitted beams, with the plate producing the largest difference in polarization between beams. The bottom right plot summarizes the results for the split ratio, as a fraction of input power, for the beamsplitters. Here it can be shown that the plate beamsplitter demonstrates the most ideal for 50/50 power splitting. For details on the experimental setup employed and the results summarized here, please click here.

Damage Threshold Specifications
Coating Designation
(Item # Prefix)
Damage Threshold
BSW 2 J/cm2 (Ø0.157 mm, 10 ns, 10Hz, at 810 nm)

Damage Threshold Data for Thorlabs' 700 - 1100 nm AR-Coated 50:50 UV Fused Silica Beamsplitters

The specifications to the right are measured data for Thorlabs' 700 - 1100 nm AR-coated UV fused silica beamsplitters. Damage threshold specifications are constant for all 50:50 AR-coated 700 - 1100 nm UV fused silica beamsplitters.

 

Laser Induced Damage Threshold Tutorial

The following is a general overview of how laser induced damage thresholds are measured and how the values may be utilized in determining the appropriateness of an optic for a given application. When choosing optics, it is important to understand the Laser Induced Damage Threshold (LIDT) of the optics being used. The LIDT for an optic greatly depends on the type of laser you are using. Continuous wave (CW) lasers typically cause damage from thermal effects (absorption either in the coating or in the substrate). Pulsed lasers, on the other hand, often strip electrons from the lattice structure of an optic before causing thermal damage. Note that the guideline presented here assumes room temperature operation and optics in new condition (i.e., within scratch-dig spec, surface free of contamination, etc.). Because dust or other particles on the surface of an optic can cause damage at lower thresholds, we recommend keeping surfaces clean and free of debris. For more information on cleaning optics, please see our Optics Cleaning tutorial.

Testing Method

Thorlabs' LIDT testing is done in compliance with ISO/DIS 11254 and ISO 21254 specifications.

First, a low-power/energy beam is directed to the optic under test. The optic is exposed in 10 locations to this laser beam for 30 seconds (CW) or for a number of pulses (pulse repetition frequency specified). After exposure, the optic is examined by a microscope (~100X magnification) for any visible damage. The number of locations that are damaged at a particular power/energy level is recorded. Next, the power/energy is either increased or decreased and the optic is exposed at 10 new locations. This process is repeated until damage is observed. The damage threshold is then assigned to be the highest power/energy that the optic can withstand without causing damage. A histogram such as that below represents the testing of one BB1-E02 mirror.

LIDT metallic mirror
The photograph above is a protected aluminum-coated mirror after LIDT testing. In this particular test, it handled 0.43 J/cm2 (1064 nm, 10 ns pulse, 10 Hz, Ø1.000 mm) before damage.
LIDT BB1-E02
Example Test Data
Fluence # of Tested Locations Locations with Damage Locations Without Damage
1.50 J/cm2 10 0 10
1.75 J/cm2 10 0 10
2.00 J/cm2 10 0 10
2.25 J/cm2 10 1 9
3.00 J/cm2 10 1 9
5.00 J/cm2 10 9 1

According to the test, the damage threshold of the mirror was 2.00 J/cm2 (532 nm, 10 ns pulse, 10 Hz, Ø0.803 mm). Please keep in mind that these tests are performed on clean optics, as dirt and contamination can significantly lower the damage threshold of a component. While the test results are only representative of one coating run, Thorlabs specifies damage threshold values that account for coating variances.

Continuous Wave and Long-Pulse Lasers

When an optic is damaged by a continuous wave (CW) laser, it is usually due to the melting of the surface as a result of absorbing the laser's energy or damage to the optical coating (antireflection) [1]. Pulsed lasers with pulse lengths longer than 1 µs can be treated as CW lasers for LIDT discussions.

When pulse lengths are between 1 ns and 1 µs, laser-induced damage can occur either because of absorption or a dielectric breakdown (therefore, a user must check both CW and pulsed LIDT). Absorption is either due to an intrinsic property of the optic or due to surface irregularities; thus LIDT values are only valid for optics meeting or exceeding the surface quality specifications given by a manufacturer. While many optics can handle high power CW lasers, cemented (e.g., achromatic doublets) or highly absorptive (e.g., ND filters) optics tend to have lower CW damage thresholds. These lower thresholds are due to absorption or scattering in the cement or metal coating.

Linear Power Density Scaling

LIDT in linear power density vs. pulse length and spot size. For long pulses to CW, linear power density becomes a constant with spot size. This graph was obtained from [1].

Intensity Distribution

Pulsed lasers with high pulse repetition frequencies (PRF) may behave similarly to CW beams. Unfortunately, this is highly dependent on factors such as absorption and thermal diffusivity, so there is no reliable method for determining when a high PRF laser will damage an optic due to thermal effects. For beams with a high PRF both the average and peak powers must be compared to the equivalent CW power. Additionally, for highly transparent materials, there is little to no drop in the LIDT with increasing PRF.

In order to use the specified CW damage threshold of an optic, it is necessary to know the following:

  1. Wavelength of your laser
  2. Beam diameter of your beam (1/e2)
  3. Approximate intensity profile of your beam (e.g., Gaussian)
  4. Linear power density of your beam (total power divided by 1/e2 beam diameter)

Thorlabs expresses LIDT for CW lasers as a linear power density measured in W/cm. In this regime, the LIDT given as a linear power density can be applied to any beam diameter; one does not need to compute an adjusted LIDT to adjust for changes in spot size, as demonstrated by the graph to the right. Average linear power density can be calculated using the equation below. 

The calculation above assumes a uniform beam intensity profile. You must now consider hotspots in the beam or other non-uniform intensity profiles and roughly calculate a maximum power density. For reference, a Gaussian beam typically has a maximum power density that is twice that of the uniform beam (see lower right).

Now compare the maximum power density to that which is specified as the LIDT for the optic. If the optic was tested at a wavelength other than your operating wavelength, the damage threshold must be scaled appropriately. A good rule of thumb is that the damage threshold has a linear relationship with wavelength such that as you move to shorter wavelengths, the damage threshold decreases (i.e., a LIDT of 10 W/cm at 1310 nm scales to 5 W/cm at 655 nm):

CW Wavelength Scaling

While this rule of thumb provides a general trend, it is not a quantitative analysis of LIDT vs wavelength. In CW applications, for instance, damage scales more strongly with absorption in the coating and substrate, which does not necessarily scale well with wavelength. While the above procedure provides a good rule of thumb for LIDT values, please contact Tech Support if your wavelength is different from the specified LIDT wavelength. If your power density is less than the adjusted LIDT of the optic, then the optic should work for your application. 

Please note that we have a buffer built in between the specified damage thresholds online and the tests which we have done, which accommodates variation between batches. Upon request, we can provide individual test information and a testing certificate. The damage analysis will be carried out on a similar optic (customer's optic will not be damaged). Testing may result in additional costs or lead times. Contact Tech Support for more information.

Pulsed Lasers

As previously stated, pulsed lasers typically induce a different type of damage to the optic than CW lasers. Pulsed lasers often do not heat the optic enough to damage it; instead, pulsed lasers produce strong electric fields capable of inducing dielectric breakdown in the material. Unfortunately, it can be very difficult to compare the LIDT specification of an optic to your laser. There are multiple regimes in which a pulsed laser can damage an optic and this is based on the laser's pulse length. The highlighted columns in the table below outline the relevant pulse lengths for our specified LIDT values.

Pulses shorter than 10-9 s cannot be compared to our specified LIDT values with much reliability. In this ultra-short-pulse regime various mechanics, such as multiphoton-avalanche ionization, take over as the predominate damage mechanism [2]. In contrast, pulses between 10-7 s and 10-4 s may cause damage to an optic either because of dielectric breakdown or thermal effects. This means that both CW and pulsed damage thresholds must be compared to the laser beam to determine whether the optic is suitable for your application.

Pulse Duration t < 10-9 s 10-9 < t < 10-7 s 10-7 < t < 10-4 s t > 10-4 s
Damage Mechanism Avalanche Ionization Dielectric Breakdown Dielectric Breakdown or Thermal Thermal
Relevant Damage Specification No Comparison (See Above) Pulsed Pulsed and CW CW

When comparing an LIDT specified for a pulsed laser to your laser, it is essential to know the following:

Energy Density Scaling

LIDT in energy density vs. pulse length and spot size. For short pulses, energy density becomes a constant with spot size. This graph was obtained from [1].

  1. Wavelength of your laser
  2. Energy density of your beam (total energy divided by 1/e2 area)
  3. Pulse length of your laser
  4. Pulse repetition frequency (prf) of your laser
  5. Beam diameter of your laser (1/e2 )
  6. Approximate intensity profile of your beam (e.g., Gaussian)

The energy density of your beam should be calculated in terms of J/cm2. The graph to the right shows why expressing the LIDT as an energy density provides the best metric for short pulse sources. In this regime, the LIDT given as an energy density can be applied to any beam diameter; one does not need to compute an adjusted LIDT to adjust for changes in spot size. This calculation assumes a uniform beam intensity profile. You must now adjust this energy density to account for hotspots or other nonuniform intensity profiles and roughly calculate a maximum energy density. For reference a Gaussian beam typically has a maximum energy density that is twice that of the 1/e2 beam.

Now compare the maximum energy density to that which is specified as the LIDT for the optic. If the optic was tested at a wavelength other than your operating wavelength, the damage threshold must be scaled appropriately [3]. A good rule of thumb is that the damage threshold has an inverse square root relationship with wavelength such that as you move to shorter wavelengths, the damage threshold decreases (i.e., a LIDT of 1 J/cm2 at 1064 nm scales to 0.7 J/cm2 at 532 nm):

Pulse Wavelength Scaling

You now have a wavelength-adjusted energy density, which you will use in the following step.

Beam diameter is also important to know when comparing damage thresholds. While the LIDT, when expressed in units of J/cm², scales independently of spot size; large beam sizes are more likely to illuminate a larger number of defects which can lead to greater variances in the LIDT [4]. For data presented here, a <1 mm beam size was used to measure the LIDT. For beams sizes greater than 5 mm, the LIDT (J/cm2) will not scale independently of beam diameter due to the larger size beam exposing more defects.

The pulse length must now be compensated for. The longer the pulse duration, the more energy the optic can handle. For pulse widths between 1 - 100 ns, an approximation is as follows:

Pulse Length Scaling

Use this formula to calculate the Adjusted LIDT for an optic based on your pulse length. If your maximum energy density is less than this adjusted LIDT maximum energy density, then the optic should be suitable for your application. Keep in mind that this calculation is only used for pulses between 10-9 s and 10-7 s. For pulses between 10-7 s and 10-4 s, the CW LIDT must also be checked before deeming the optic appropriate for your application.

Please note that we have a buffer built in between the specified damage thresholds online and the tests which we have done, which accommodates variation between batches. Upon request, we can provide individual test information and a testing certificate. Contact Tech Support for more information.


[1] R. M. Wood, Optics and Laser Tech. 29, 517 (1998).
[2] Roger M. Wood, Laser-Induced Damage of Optical Materials (Institute of Physics Publishing, Philadelphia, PA, 2003).
[3] C. W. Carr et al., Phys. Rev. Lett. 91, 127402 (2003).
[4] N. Bloembergen, Appl. Opt. 12, 661 (1973).

In order to illustrate the process of determining whether a given laser system will damage an optic, a number of example calculations of laser induced damage threshold are given below. For assistance with performing similar calculations, we provide a spreadsheet calculator that can be downloaded by clicking the button to the right. To use the calculator, enter the specified LIDT value of the optic under consideration and the relevant parameters of your laser system in the green boxes. The spreadsheet will then calculate a linear power density for CW and pulsed systems, as well as an energy density value for pulsed systems. These values are used to calculate adjusted, scaled LIDT values for the optics based on accepted scaling laws. This calculator assumes a Gaussian beam profile, so a correction factor must be introduced for other beam shapes (uniform, etc.). The LIDT scaling laws are determined from empirical relationships; their accuracy is not guaranteed. Remember that absorption by optics or coatings can significantly reduce LIDT in some spectral regions. These LIDT values are not valid for ultrashort pulses less than one nanosecond in duration.

Intensity Distribution
A Gaussian beam profile has about twice the maximum intensity of a uniform beam profile.

CW Laser Example
Suppose that a CW laser system at 1319 nm produces a 0.5 W Gaussian beam that has a 1/e2 diameter of 10 mm. A naive calculation of the average linear power density of this beam would yield a value of 0.5 W/cm, given by the total power divided by the beam diameter:

CW Wavelength Scaling

However, the maximum power density of a Gaussian beam is about twice the maximum power density of a uniform beam, as shown in the graph to the right. Therefore, a more accurate determination of the maximum linear power density of the system is 1 W/cm.

An AC127-030-C achromatic doublet lens has a specified CW LIDT of 350 W/cm, as tested at 1550 nm. CW damage threshold values typically scale directly with the wavelength of the laser source, so this yields an adjusted LIDT value:

CW Wavelength Scaling

The adjusted LIDT value of 350 W/cm x (1319 nm / 1550 nm) = 298 W/cm is significantly higher than the calculated maximum linear power density of the laser system, so it would be safe to use this doublet lens for this application.

Pulsed Nanosecond Laser Example: Scaling for Different Pulse Durations
Suppose that a pulsed Nd:YAG laser system is frequency tripled to produce a 10 Hz output, consisting of 2 ns output pulses at 355 nm, each with 1 J of energy, in a Gaussian beam with a 1.9 cm beam diameter (1/e2). The average energy density of each pulse is found by dividing the pulse energy by the beam area:

Pulse Energy Density

As described above, the maximum energy density of a Gaussian beam is about twice the average energy density. So, the maximum energy density of this beam is ~0.7 J/cm2.

The energy density of the beam can be compared to the LIDT values of 1 J/cm2 and 3.5 J/cm2 for a BB1-E01 broadband dielectric mirror and an NB1-K08 Nd:YAG laser line mirror, respectively. Both of these LIDT values, while measured at 355 nm, were determined with a 10 ns pulsed laser at 10 Hz. Therefore, an adjustment must be applied for the shorter pulse duration of the system under consideration. As described on the previous tab, LIDT values in the nanosecond pulse regime scale with the square root of the laser pulse duration:

Pulse Length Scaling

This adjustment factor results in LIDT values of 0.45 J/cm2 for the BB1-E01 broadband mirror and 1.6 J/cm2 for the Nd:YAG laser line mirror, which are to be compared with the 0.7 J/cm2 maximum energy density of the beam. While the broadband mirror would likely be damaged by the laser, the more specialized laser line mirror is appropriate for use with this system.

Pulsed Nanosecond Laser Example: Scaling for Different Wavelengths
Suppose that a pulsed laser system emits 10 ns pulses at 2.5 Hz, each with 100 mJ of energy at 1064 nm in a 16 mm diameter beam (1/e2) that must be attenuated with a neutral density filter. For a Gaussian output, these specifications result in a maximum energy density of 0.1 J/cm2. The damage threshold of an NDUV10A Ø25 mm, OD 1.0, reflective neutral density filter is 0.05 J/cm2 for 10 ns pulses at 355 nm, while the damage threshold of the similar NE10A absorptive filter is 10 J/cm2 for 10 ns pulses at 532 nm. As described on the previous tab, the LIDT value of an optic scales with the square root of the wavelength in the nanosecond pulse regime:

Pulse Wavelength Scaling

This scaling gives adjusted LIDT values of 0.08 J/cm2 for the reflective filter and 14 J/cm2 for the absorptive filter. In this case, the absorptive filter is the best choice in order to avoid optical damage.

Pulsed Microsecond Laser Example
Consider a laser system that produces 1 µs pulses, each containing 150 µJ of energy at a repetition rate of 50 kHz, resulting in a relatively high duty cycle of 5%. This system falls somewhere between the regimes of CW and pulsed laser induced damage, and could potentially damage an optic by mechanisms associated with either regime. As a result, both CW and pulsed LIDT values must be compared to the properties of the laser system to ensure safe operation.

If this relatively long-pulse laser emits a Gaussian 12.7 mm diameter beam (1/e2) at 980 nm, then the resulting output has a linear power density of 5.9 W/cm and an energy density of 1.2 x 10-4 J/cm2 per pulse. This can be compared to the LIDT values for a WPQ10E-980 polymer zero-order quarter-wave plate, which are 5 W/cm for CW radiation at 810 nm and 5 J/cm2 for a 10 ns pulse at 810 nm. As before, the CW LIDT of the optic scales linearly with the laser wavelength, resulting in an adjusted CW value of 6 W/cm at 980 nm. On the other hand, the pulsed LIDT scales with the square root of the laser wavelength and the square root of the pulse duration, resulting in an adjusted value of 55 J/cm2 for a 1 µs pulse at 980 nm. The pulsed LIDT of the optic is significantly greater than the energy density of the laser pulse, so individual pulses will not damage the wave plate. However, the large average linear power density of the laser system may cause thermal damage to the optic, much like a high-power CW beam.


Posted Comments:
craig  (posted 2013-11-05 18:37:48.86)
Found the scratch/dig in the "info" button link next to the item.
craig  (posted 2013-11-05 18:35:21.06)
What is the substrate scratch/dig polish?
axel.paul  (posted 2013-02-22 08:57:09.45)
Hello, I have a technical question about your beam splitter: What happens when a strong reflection is impinging the beamsplitter in the reverse direction. Will the same splitting ratio be applied? (My aim is to get a beam through a element, and reflections should be deflected) Thank you very much!
cdaly  (posted 2013-03-04 13:20:00.0)
Response from Chris at Thorlabs: Fundamentally, the beam splitter will work in reverse. The reason we recommend being incidence on the beam splitter coated side first is because this will result in a smaller ghosting affect. This would b slightly higher if passing through the uncoated face first.
cdaly  (posted 2012-12-05 16:57:00.0)
Thank you for using our feedback feature. If the wedge on this beamsplitter creates too much deviation of the beam from the cage system, would it be possible instead to use the BS029 700-1100nm 10:90 beamsplitter cube within the CM1-4ER cage cube mount?
farrell  (posted 2012-11-28 04:28:20.533)
I would like to achieve 10:90 splitting using BSX11 but I would also like to keep the transmitted beam to remain along he optical axis and not diverge. BSX11 has a wedge back surface. So you have suggestions on how to achieve this?
tcohen  (posted 2012-09-23 21:47:00.0)
Response from Tim at Thorlabs: At your wavelength and AOI the unpolarized R will be approximately ~50%. P polarized light would be approximately ~44% R. I will contact you with some typical data for this AOI.
alsturl  (posted 2012-09-18 14:53:40.0)
I'm considering using your BSW11 (50:50 BS) at a 30 degree angle of incidence. The wavelength is 800nm and the beam is p-polarized. How do the transmission and reflectance specs change when at 30 deg AOI? Thanks.
tcohen  (posted 2012-07-10 13:04:00.0)
Response from Tim at Thorlabs: Thank you for your interest in our beamsplitters. We do offer a wedged rectangular plate beamsplitter (BSF2550). To be able to extend a quote for a custom rectangular version of our coated UVFS BB Plate Beamsplitters, we would require more information on the desired specs, dimensions and quantity. I will contact you to go over your optic in more detail.
tds  (posted 2012-07-09 22:07:25.0)
can these wedged beamsplitters be provided in rectangular format?
tcohen  (posted 2012-05-11 16:52:00.0)
Update from Tim at Thorlabs: Testing the BSS11 at 980nm and 45 AOI, the polarization was able to be manipulated from perfectly linear (from a calcite polarizer) to <0.5 degrees ellipticity, with 0 being perfectly linear and 45 degrees being perfectly circular.
tcohen  (posted 2012-05-10 15:30:00.0)
Response from Tim at Thorlabs: Thank you for your feedback! Polarization effects should be minimal. To confirm, we are testing and I will update you with the data shortly.
ahambi  (posted 2012-05-02 14:04:00.0)
Dear Thorlabs team, if I have perfectly orthogonal incoming linear polarization and I want to use the fused silica splitter to couple 30 % out, how much will the orthogonality in the transmitted 70 % be distorted?

Thorlabs' portfolio contains many different kinds of beamsplitters, which can split beams by intensity or by polarization. We offer plate and cube beamsplitters, though other form factors exist, including pellicle and birefringent crystal. Many of our beamsplitters come in premounted or unmounted variants. Below is a complete listing of our beamsplitter offerings. To explore the available types, wavelength ranges, splitting/extinction ratios, transmission, and available sizes for each beamsplitter category, click More [+] in the appropriate row below.

Non-Polarizing Beamsplitters

Plate Beamsplitters
Cube Beamsplitters
Pellicle Beamsplitters
  • 45° AOI Unless Otherwise Noted

Polarizing Beamsplitters

Plate Beamsplitters
Cube Beamsplitters
Birefringent Crystal Beamsplitters
  • Mounted in a protective box, unthreaded ring, or cylinder.
  • Available unmounted or mounted in a protective box or unthreaded cylinder.

Other Beamsplitters

Other Beamsplitters

10:90 (R:T) Plate Beamsplitters

Click for Raw Data in the 300 - 2500 nm Range
Transmission and reflectance data for the broadband plate beamsplitters coated for 700 - 1100 nm was obtained for a 45° angle of incidence (AOI). The shaded region denotes the stated beamsplitter coating range. Reflectance and transmission were measured separately using a Perkin Elmer Lambda 950 UV/VIS/NIR spectrophotometer with a calcite polarizer attachment.

Item # Size Thickness Wedge Angle Split Ratio (R:T) Overall Performance Info
BSN05 Ø1/2" 3 mm 30 arcmin 10:90 Tabs = 90 ± 8%, Rabs = 10 ± 8%,
Tabs + Rabs > 99%
|Ts - Tp| < 35% and |Rs - Rp| < 35%, 45° AOI
info
BSN11 Ø1" 5 mm 30 arcmin 10:90 info
BSN11R 25 mm x 36 mm 1.0 mm No Wedge 10:90 info
BSN17 Ø2" 8 mm 30 arcmin 10:90 info
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
BSN05 Support Documentation
BSN05Customer Inspired! Ø1/2" 10:90 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 3 mm
$104.81
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BSN11 Support Documentation
BSN11Customer Inspired! Ø1" 10:90 (R:T) UVFS Plate Beamsplitter, Coating: 700-1100 nm, t = 5 mm
$137.42
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BSN11R Support Documentation
BSN11R25 x 36 mm 10:90 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 1 mm
$144.41
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BSN17 Support Documentation
BSN17Customer Inspired! Ø2" 10:90 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 8 mm
$220.11
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30:70 (R:T) Plate Beamsplitters

Click for Raw Data in the 300 - 2500 nm Range
Transmission and reflectance data for the broadband plate beamsplitters coated for 700 - 1100 nm was obtained for a 45° angle of incidence (AOI). The shaded region denotes the stated beamsplitter coating range. Reflectance and transmission were measured separately using a Perkin Elmer Lambda 950 UV/VIS/NIR spectrophotometer with a calcite polarizer attachment.

Item # Size Thickness Wedge Angle Split Ratio (R:T) Overall Performance Info
BSS05 Ø1/2" 3 mm 30 arcmin 30:70 Tabs = 70 ± 8%, Rabs = 30 ± 8%,
Tabs + Rabs > 99%
|Ts - Tp| < 35% and |Rs - Rp| < 35%, 45° AOI
info
BSS11 Ø1" 5 mm 30 arcmin 30:70 info
BSS11R 25 mm x 36 mm 1.0 mm No Wedge 30:70 info
BSS17 Ø2" 8 mm 30 arcmin 30:70 info
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
BSS05 Support Documentation
BSS05Customer Inspired! Ø1/2" 30:70 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 3 mm
$89.96
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BSS11 Support Documentation
BSS11 Ø1" 30:70 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 5 mm
$111.81
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BSS11R Support Documentation
BSS11R25 x 36 mm 30:70 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 1 mm
$131.61
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BSS17 Support Documentation
BSS17Customer Inspired! Ø2" 30:70 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 8 mm
$193.33
3 weeks

50:50 (R:T) Plate Beamsplitters

Click for Raw Data in the 300 - 2500 nm Range
Transmission and reflectance data for the broadband plate beamsplitters coated for 700 - 1100 nm was obtained for a 45° angle of incidence (AOI). The shaded region denotes the stated beamsplitter coating range. Reflectance and transmission were measured separately using a Perkin Elmer Lambda 950 UV/VIS/NIR spectrophotometer with a calcite polarizer attachment.

Item # Size Thickness Wedge Angle Split Ratio (R:T) Overall Performance Info
BSW05 Ø1/2" 3 mm 30 arcmin 50:50 Tabs = 50 ± 8%, Rabs = 50 ± 8%,
Tabs + Rabs > 99%
|Ts - Tp| < 35% and |Rs - Rp| < 35%, 45° AOI
info
BSW11 Ø1" 5 mm 30 arcmin 50:50 info
BSW11R 25 mm x 36 mm 1.0 mm No Wedge 50:50 info
BSW17 Ø2" 8 mm 30 arcmin 50:50 info
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
BSW05 Support Documentation
BSW05Ø1/2" 50:50 UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 3 mm
$89.96
Today
BSW11 Support Documentation
BSW11Ø1" 50:50 UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 5 mm
$111.81
Today
BSW11R Support Documentation
BSW11RCustomer Inspired! 25 x 36 mm 50:50 UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 1 mm
$131.61
Today
BSW17 Support Documentation
BSW17Ø2" 50:50 UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 8 mm
$193.33
Today

70:30 (R:T) Plate Beamsplitters

Click for Raw Data in the 300 - 2600 nm Range
Transmission and reflectance data for the broadband plate beamsplitters coated for 700 - 1100 nm was obtained for a 45° angle of incidence (AOI). The shaded region denotes the stated beamsplitter coating range. Reflectance and transmission were measured separately using a Perkin Elmer Lambda 950 UV/VIS/NIR spectrophotometer with a calcite polarizer attachment.

Item # Size Thickness Wedge Angle Split Ratio (R:T) Overall Performance Info
BST05 Ø1/2" 3 mm 30 arcmin 70:30 Tabs = 30 ± 8%, Rabs = 70 ± 8%,
Tabs + Rabs > 99%
|Ts - Tp| < 35% and |Rs - Rp| < 35%, 45° AOI
info
BST11 Ø1" 5 mm 30 arcmin 70:30 info
BST11R 25 mm x 36 mm 1.0 mm No Wedge 70:30 info
BST17 Ø2" 8 mm 30 arcmin 70:30 info
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
BST05 Support Documentation
BST05Customer Inspired! Ø1/2" 70:30 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 3 mm
$89.96
Today
BST11 Support Documentation
BST11Ø1" 70:30 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 5 mm
$111.81
Today
BST11R Support Documentation
BST11R25 x 36 mm 70:30 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 1 mm
$131.61
Today
BST17 Support Documentation
BST17Customer Inspired! Ø2" 70:30 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 8 mm
$193.33
Today

90:10 (R:T) Plate Beamsplitters

Click for Raw Data in the 300 - 2500 nm Range
Transmission and reflectance data for the broadband plate beamsplitters coated for 700 - 1100 nm was obtained for a 45° angle of incidence (AOI). The shaded region denotes the stated beamsplitter coating range. Reflectance and transmission were measured separately using a Perkin Elmer Lambda 950 UV/VIS/NIR spectrophotometer with a calcite polarizer attachment.

Item # Size Thickness Wedge Angle Split Ratio (R:T) Overall Performance Info
BSX05 Ø1/2" 3 mm 30 arcmin 90:10 Tabs = 10 ± 8%, Rabs = 90 ± 8%,
Tabs + Rabs > 99%
|Ts - Tp| < 35% and |Rs - Rp| < 35%, 45° AOI
info
BSX11 Ø1" 5 mm 30 arcmin 90:10 info
BSX11R 25 mm x 36 mm 1.0 mm No Wedge 90:10 info
BSX17 Ø2" 8 mm 30 arcmin 90:10 info
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Universal Price Available
BSX05 Support Documentation
BSX05Customer Inspired! Ø1/2" 90:10 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 3 mm
$104.81
Today
BSX11 Support Documentation
BSX11Customer Inspired! Ø1" 90:10 (R:T) UVFS Plate Beamsplitter, Coating: 700-1100 nm, t = 5 mm
$137.42
Today
BSX11R Support Documentation
BSX11R25 x 36 mm 90:10 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 1 mm
$144.41
Today
BSX17 Support Documentation
BSX17Customer Inspired! Ø2" 90:10 (R:T) UVFS Plate Beamsplitter, Coating: 700 - 1100 nm, t = 8 mm
$220.11
Today