Mounted UV Fused Silica Reflective ND Filters
- UV to IR Spectral Range (200 - 1200 nm)
- Metallic Nickel Coating on UV Fused Silica Substrate
- Optical Densities from 0.1 to 4.0 Available
NDUV2R02A
Ø50 mm
NDUV520A
Ø1/2"
NDUV503A
Ø1/2"
NDUV02A
Ø25 mm
NUK01
Box of 10 Mounted
Ø25 mm UVFS Filters
Please Wait
Neutral Density Filter Selection Guide |
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Absorptive | |
Uncoated (400 - 650 nm) |
Mounted |
Unmounted | |
Uncoated (1000 - 2600 nm) |
Mounted |
Unmounted | |
AR Coated (350 - 700 nm) |
Mounted |
Unmounted | |
AR Coated (650 - 1050 nm) |
Mounted |
Unmounted | |
AR Coated (1050 - 1700 nm) |
Mounted |
Unmounted | |
Variable | |
Reflective | |
UV Fused Silica (200 - 1200 nm) |
Mounted |
Unmounted | |
N-BK7 (350 - 1100 nm) |
Mounted |
Unmounted | |
ZnSe (2 - 16 µm) |
Mounted |
Unmounted | |
Wedged UVFS (200 - 1200 nm) | |
Wedged N-BK7 (350 - 1100 nm) | |
Variable | |
Neutral Density Filter Kits |
Click to Enlarge
Transmission and Optical Density of Reflective UVFS ND Filters
Features
- Optimized for Light Attenuation in the UV
- Mounted Ø1/2", Ø25 mm, or Ø50 mm Filters
- SM05-, SM1-, or SM2- Threaded Mounts
- Optical Densities Available from 0.1 - 4.0
- Optimized for 200 to 400 nm
- Usable from 200 to 1200 nm
- Ø25 mm Filter Kit Available
Thorlabs offers reflective neutral density (ND) filters made from UV fused silica substrates with nickel coatings deposited on one side, which provides a flat spectral response. These mounted metallic filters are usable in the 200 - 1200 nm spectral range and are available in Ø1/2", Ø25 mm, and Ø50 mm versions. The Ø1/2" mounted filters come in SM05 (0.535"-40)-threaded lens tubes, while the Ø25 mm and Ø50 mm versions are housed in SM1 (1.035"-40)- and SM2 (2.035"-40 )-threaded lens tubes respectively. Each filter is engraved with the part number, filter type (i.e., reflective), and optical density. For other mounting options and wavelength ranges, please see the Selection Guide table on the right.
The UV fused silica substrate used in these filters exhibits high transmission and virtually no laser-induced fluorescence, as measured at 193 nm, making it an ideal choice for applications from the UV to the near IR. While the spectral range's lower limit of 200 nm is limited by the absorption of the light by the substrate, UV fused silica provides good transmission up to 2.1 µm, and thus the upper limit of 1200 nm is dependent on the increased opacity of the nickel coating. The optical density (OD) for each filter is specified at the design wavelength of 300 nm to facilitate their use in the UV; some variation in the OD will occur over the usable range. For plots showing the typical performance of the filters from 200 to 2600 nm, click on in the row corresponding to the desired filter in the tables below.
Unprotected metal coatings like this should only be cleaned by blown air, never touched, as contact may cause scratching to the unprotected surface. Although these are reflective ND filters, the nickel coating does absorb some of the incident light, which limits the use of these filters to low-power applications. Nickel is resistant to aging under normal conditions; however, it will oxidize at elevated temperatures. To prevent oxidation, Thorlabs recommends using these ND filters at temperatures below 100 °C. To achieve the best performance light should be incident on the side with the nickel coating.
If desired, a mounted filter can be removed from its housing by unscrewing the retaining ring that secures the filter to the mount. Thorlabs offers a range of spanner wrenches that are an ideal match to these retaining rings. The round filters listed on this page are also sold unmounted. The equivalent unmounted filter is listed in the drawing for each mounted filter, accessible through the red docs icons () below.
Ten of the Ø25 mm mounted UVFS reflective ND filters are also offered in the NUK01 filter kit, sold below. This kit comes in the KT01 hard-plastic storage box with labeled foam inserts to organize the optics. The KT01 box is also sold separately below for storage of individually purchased mounted filters.
Optical Density and Transmission
Optical density (OD) indicates the attenuation factor provided by an optical filter, i.e. how much it reduces the optical power of an incident beam. OD is related to the transmission, T, by the equation
where T is a value between 0 and 1. Choosing an ND filter with a higher optical density will translate to lower transmission and greater absorption of the incident light. For higher transmission and less absorption, a lower optical density would be appropriate. As an example, if a filter with an OD of 2 results in a transmission value of 0.01, this means the filter attenuates the beam to 1% of the incident power. Please note that the transmission data for our neutral density filters is provided in percent (%).
Please note that these products are not designed for use as laser safety equipment. For lab safety, Thorlabs offers an extensive line of safety and blackout products, including beam blocks, that significantly reduce exposure to stray light.
Filter Size | Ø1/2" | Ø25 mm | Ø50 mm |
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Substrate Material | UV Fused Silicaa | ||
Front Surface Coating | Nickel | ||
Wavelength Range | Optimized for 200 - 400 nm Usable from 200 - 1200 nm |
||
Optical Density Toleranceb | ±5% | ||
Optic Diameter | 1/2" | 25.0 mm | 50.0 mm |
Optic Diameter Tolerance | +0.00 / -0.20 mm | ||
Clear Aperture | >Ø11.0 mm | >Ø22.5 mm | >Ø45.0 mm |
Housing Thread | SM05 (0.535"-40) | SM1 (1.035"-40) | SM2 (2.035"-40) |
Housing Diameter | 0.70" (17.8 mm)c | 1.20" (30.5 mm) | 2.20" (55.9 mm) |
Filter Thickness | 1 mm | 2 mm | |
Thickness Tolerance | ±0.10 mm | ||
Surface Flatness @ 633 nm | <2λ | <2λ per Ø25.0 mm | |
Parallelism | <20 arcmin | <30 arcsec | <30 arcsec |
Surface Quality | 40-20 Scratch-Dig | ||
Operating Temperatured | <100 °C |
Optical Density | Damage Threshold |
---|---|
0.3 | 0.025 J/cm2 (355 nm, 10 ns, 10 Hz, Ø0.772 mm) |
1.0 | 0.05 J/cm2 (355 nm, 10 ns, 10 Hz, Ø0.772 mm) |
2.0 | 0.075 J/cm2 (355 nm, 10 ns, 10 Hz, Ø0.772 mm) |
Damage Threshold Specifications | |
---|---|
Optical Density | Damage Threshold |
0.3 | 0.025 J/cm2 (355 nm, 10 ns, 10 Hz, Ø0.772 mm) |
1.0 | 0.05 J/cm2 (355 nm, 10 ns, 10 Hz, Ø0.772 mm) |
2.0 | 0.075 J/cm2 (355 nm, 10 ns, 10 Hz, Ø0.772 mm) |
Damage Threshold Data for Thorlabs' UV Reflective ND Filters
The specifications to the right are measured data for Thorlabs' UV reflective ND filters. Damage threshold specifications are constant for a given optical density, regardless of the size of the filter.
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.
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.
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.
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:
- Wavelength of your laser
- Beam diameter of your beam (1/e2)
- Approximate intensity profile of your beam (e.g., Gaussian)
- 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):
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:
- Wavelength of your laser
- Energy density of your beam (total energy divided by 1/e2 area)
- Pulse length of your laser
- Pulse repetition frequency (prf) of your laser
- Beam diameter of your laser (1/e2 )
- 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):
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:
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.
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:
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:
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:
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:
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:
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.
Thorlabs' Threading Specifications
Thorlabs' lens tubes utilize a series of non-standard threadings. Threading specifications are given below for our SM threadings utilized in our lens tube and cage system components so that you can machine mating components to suit your application. We also offer products with C-Mount and RMS threadings, and the specifications for these threadings are also given below. Please note that other manufacturers may have different tolerances for these threads. For other thread specifications that are not listed here, please contact Tech Support.
SM05 Threading: Ø1/2" Lens Tubes, 16 mm Cage Systems | |||
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External Thread, 0.535"-40.0, UNS-2A | Internal Thread, 0.535"-40.0, UNS-2B | ||
Max Major Diameter | 0.5340" | Min Major Diameter | 0.5350" |
Min Major Diameter | 0.5289" | Min Pitch Diameter | 0.5188" |
Max Pitch Diameter | 0.5178" | Max Pitch Diameter | 0.5230" |
Min Pitch Diameter | 0.5146" | Min Minor Diameter (and 83.3% of thread) | 0.508" |
Max Minor Diameter | 0.5069" | Max Minor Diameter (and 64.9% of thread) | 0.514" |
RMS Threading: Objective, Scan, and Tube Lenses | |||
---|---|---|---|
External Thread, 0.800"-36.0, UNS-2A | Internal Thread, 0.800"-36.0, UNS-2B | ||
Max Major Diameter | 0.7989" | Min Major Diameter | 0.8000" |
Min Major Diameter | 0.7934" | Min Pitch Diameter | 0.7820" |
Max Pitch Diameter | 0.7809" | Max Pitch Diameter | 0.7866" |
Min Pitch Diameter | 0.7774" | Min Minor Diameter (and 83.3% of thread) | 0.770" |
Max Minor Diameter | 0.7688" | Max Minor Diameter (and 64.9% of thread) | 0.777" |
C-Mount Threading: Machine Vision Lenses, CCD/CMOS Cameras | |||
---|---|---|---|
External Thread, 1.000"-32.0, UN-2A | Internal Thread, 1.000"-32.0, UN-2B | ||
Max Major Diameter | 0.9989" | Min Major Diameter | 1.0000" |
Min Major Diameter | 0.9929" | Min Pitch Diameter | 0.9797" |
Max Pitch Diameter | 0.9786" | Max Pitch Diameter | 0.9846" |
Min Pitch Diameter | 0.9748" | Min Minor Diameter (and 83.3% of thread) | 0.966" |
Max Minor Diameter | 0.9651" | Max Minor Diameter (and 64.9% of thread) | 0.974" |
SM1 Threading: Ø1" Lens Tubes, 30 mm Cage Systems | |||
---|---|---|---|
External Thread, 1.035"-40.0, UNS-2A | Internal Thread, 1.035"-40.0, UNS-2B | ||
Max Major Diameter | 1.0339" | Min Major Diameter | 1.0350" |
Min Major Diameter | 1.0288" | Min Pitch Diameter | 1.0188" |
Max Pitch Diameter | 1.0177" | Max Pitch Diameter | 1.0234" |
Min Pitch Diameter | 1.0142" | Min Minor Diameter (and 83.3% of thread) | 1.008" |
Max Minor Diameter | 1.0068" | Max Minor Diameter (and 64.9% of thread) | 1.014" |
SM30 Threading: Ø30 mm Lens Tubes | |||
---|---|---|---|
External Thread, M30.5x0.5 | Internal Thread, M30.5x0.5 | ||
Max Major Diameter | 30.480 mm | Min Major Diameter | 30.500 mm |
Min Major Diameter | 30.371 mm | Min Pitch Diameter | 30.175 mm |
Max Pitch Diameter | 30.155 mm | Max Pitch Diameter | 30.302 mm |
Min Pitch Diameter | 30.059 mm | Min Minor Diameter (and 83.3% of thread) | 29.959 mm |
Max Minor Diameter | 29.938 mm | Max Minor Diameter (and 64.9% of thread) | 30.094 mm |
SM1.5 Threading: Ø1.5" Lens Tubes | |||
---|---|---|---|
External Thread, 1.535"-40, UNS-2A | Internal Thread, 1.535"-40, UNS-2B | ||
Max Major Diameter | 1.5339" | Min Major Diameter | 1.535" |
Min Major Diameter | 1.5288" | Min Pitch Diameter | 1.5188" |
Max Pitch Diameter | 1.5177" | Max Pitch Diameter | 1.5236" |
Min Pitch Diameter | 1.5140" | Min Minor Diameter (and 83.3% of thread) | 1.508" |
Max Minor Diameter | 1.5068" | Max Minor Diameter (and 64.9% of thread) | 1.514" |
SM2 Threading: Ø2" Lens Tubes, 60 mm Cage Systems | |||
---|---|---|---|
External Thread, 2.035"-40.0, UNS-2A | Internal Thread, 2.035"-40.0, UNS-2B | ||
Max Major Diameter | 2.0338" | Min Major Diameter | 2.0350" |
Min Major Diameter | 2.0287" | Min Pitch Diameter | 2.0188" |
Max Pitch Diameter | 2.0176" | Max Pitch Diameter | 2.0239" |
Min Pitch Diameter | 2.0137" | Min Minor Diameter (and 83.3% of thread) | 2.008" |
Max Minor Diameter | 2.0067" | Max Minor Diameter (and 64.9% of thread) | 2.014" |
SM3 Threading: Ø3" Lens Tubes | |||
---|---|---|---|
External Thread, 3.035"-40.0, UNS-2A | Internal Thread, 3.035"-40.0, UNS-2B | ||
Max Major Diameter | 3.0337" | Min Major Diameter | 3.0350" |
Min Major Diameter | 3.0286" | Min Pitch Diameter | 3.0188" |
Max Pitch Diameter | 3.0175" | Max Pitch Diameter | 3.0242" |
Min Pitch Diameter | 3.0133" | Min Minor Diameter (and 83.3% of thread) | 3.008" |
Max Minor Diameter | 3.0066" | Max Minor Diameter (and 64.9% of thread) | 3.014" |
Posted Comments: | |
lars.kreilkamp
 (posted 2019-01-04 10:43:42.343) Can you provide data on the difference in optical density for p-polarized and s-polarized light when the filters are used under an angle (e.g. at 45° or 22.5°)?
Thank you,
Lars nbayconich
 (posted 2019-02-28 03:32:21.0) Thank you for contacting Thorlabs. We will be adding additional plots to our website in the near future regarding the S and P polarization states of these filters. In the meantime we can provide scan services for individual optics upon request. I will reach out to you directly to discuss our scanning capabilities. mliphardt
 (posted 2017-11-20 15:34:10.43) Your product page contains a graph that shows: Transmission and Optical Density of Reflective UVFS ND Filters.
Could you send the data in tabulated form to me?
Thank you,
Martin nbayconich
 (posted 2017-12-26 10:48:29.0) Thank you for contacting Thorlabs. I will reach out to you directly with the raw data. Andreas.Brand
 (posted 2013-11-21 14:42:54.197) Hi,
you should give the filters a fixed angle of some degrees so that any reflections are deviated off axis and won't produce ghost images close to the actual image when used with a camera i.e.!
kind regards
Andreas Brand pbui
 (posted 2013-11-21 12:09:44.0) Response from Phong at Thorlabs: Thank you for your feedback. I will discuss your comments with our optics department. We are constantly looking for ways to improve our products and will consider your suggestion of adding the wedge to our ND filters to eliminate ghost reflections for imaging applications. tcohen
 (posted 2013-01-02 11:00:00.0) Response from Tim at Thorlabs: We do not yet have tested data on the NDUV. However, the performance of our ND filter line, assuming a 5mm 532nm beam, could handle your 10W/cm^2. pantoine
 (posted 2012-12-20 11:17:14.013) What is the damage threshold for the UV reflective ND filters with CW laser operating at 532nm?
The 0.75W/cm2 in the specifications looks pretty low? Typically my laser intensity exceeds slightly 10W/cm2?
Thank you for your feedback Tyler
 (posted 2008-10-03 09:22:54.0) A response from Tyler at Thorlabs: The presentation has been reworked and some performance plots added. Thank you for taking the time to point what additional information was needed to make a decision on the suitability of our product for your application. thorlabs
 (posted 2008-09-08 18:51:40.0) Wideband or not? The overview states
1. "designed to be used in the 200-400 nm", and
2. "flat spectral response from the VIS to the NIR".
If #2 is correct, there is no reason not to use this
in the visible and infrared. A plot of OD vs wavelength
would be a great addition.
Poor wording: "A metallic Inconel coating is used to attenuate the
light in these filters because of its durability and flat spectral
response from the VIS to the NIR. However, Inconel will oxidize if used
in an environment where the temperature is in excess of 100 °C."
The "however" does not make sense here, since the two sentences refer to
completely different properties of the filter. Tyler
 (posted 2008-06-30 13:52:04.0) A response from Tyler at Thorlabs to tom.burton: Because this product can be used over an extremely wide wavelength range it would be difficult to provide a comprehensive damage threshold specification. As a result, the number provided is conservatively low. If you end up using this product, consider posting the power density and wavelength information from your application so that others in the scientific community may benefit from your experience. This forum is intended to be used as a way for people at Thorlabs to communicate with our customers and as a way for our customers to share their experiences with each other. An engineer will be in contact with you to see if we can offer further guidance. tom.burton
 (posted 2008-06-23 17:29:30.0) cant imagine .75W/cm^2 is right on UV REFLECTIVE ND FILTERS. |