Full Aperture Obstruction Targets
![](https://www.thorlabs.com/Images/GuideImages/16113_FA_Obstruction_Targets_1.jpg)
- Low-Reflectivity Chrome Targets: Ø50 µm - Ø2500 µm
- Chrome OD ≥2.5 for the 400 - 1050 nm Wavelength Range
- Ø1" Soda Lime Glass Substrates
- >Ø22.86 mm Clear Aperture
R1D50P
Ø50 µm
Obstruction Target
R1D500P
Ø500 µm Obstruction Target
R1D2500P
Ø2500 µm Obstruction Target
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General Specifications | |
---|---|
Substrate | Soda-Lime-Glass |
Substrate Thickness | 1.5 ± 0.2 mm |
Substrate Diameter | 25.4 +0.0 / -0.1 mm |
Clear Aperture | >22.86 mm |
Obstruction Centration Tolerancea | ±0.2 mm |
Chrome Optical Density (OD) | ≥2.5 (400 - 1050 nm) |
Transmitted Wavefront Error | <λ @ 633 nm |
Surface Quality | 60-40 Scratch-Dig |
Features
- Low-Reflectivity Chrome Obstruction Targets: Ø50 µm - Ø2500 µm
- Obstructions Centered on Ø1" Soda Lime Glass Substrates
- Chrome OD ≥2.5 (400 - 1050 nm)
- >Ø22.86 mm Clear Aperture
Thorlabs' Full Aperture Obstruction Targets consist of a low-reflectivity chrome obstruction centered on a soda-lime glass substrate. The full aperture opening outside the obstruction diameter is >Ø22.86 mm. They are designed for applications such as zero-order beam blocking, investigating stray light, darkfield microscopy, or phase imaging.
The positive obstructions consist of low-reflectivity (AR coated) chrome, which reduces back reflections from the opaque chrome target improving imaging contrast. The AR coating results in < 10% light reflected from the target from 300 - 500 nm. Please see the Graphs tab for data on the AR coating over a wider wavelength range. The chrome target also provides an OD ≥2.5 from 400 - 1050 nm.
The targets can be secured in Ø1" optic mounts; translation mounts are available for precise target alignment along the XY or XYZ axes.
Item # | R1D50P | R1D100P | R1D200P | R1D300P | R1D400P | R1D500P | R1D1000P | R1D1500P | R1D2000P | R1D2500P |
---|---|---|---|---|---|---|---|---|---|---|
Obstruction Diameter | Ø50 µm | Ø100 µm | Ø200 µm | Ø300 µm | Ø400 µm | Ø500 µm | Ø1000 µm | Ø1500 µm | Ø2000 µm | Ø2500 µm |
Obstruction Diameter Tolerance | ±2 µm | ±5 µm | ±10 µm | ±15 µm | ±20 µm |
![Substrates Spectra](https://www.thorlabs.com/images/TabImages/SodaLime_Transmission_G1-400.gif)
Click to Enlarge
Click Here to Download Transmission Data
This graph shows the transmission of the soda lime glass substrate.
![Substrates Spectra](https://www.thorlabs.com/images/TabImages/FA_Obstruction_Targets_Reflectance_A1-400.gif)
Click to Enlarge
Click Here to Download Target Data
This graph shows the spectral reflectance of low-reflectivity chrome (blue line) and soda-lime-glass (red line). The reflectance data of the soda-lime glass accounts for reflection returning from both the front and back surfaces of the substrate. In the 300 - 500 nm range, the low-reflectivity chrome positive obstruction targets reflect <10% of incident light.
![Substrates Spectra](https://www.thorlabs.com/images/TabImages/LR_Chrome_OD_A1-400.gif)
Click to Enlarge
Click Here to Download Target Data
The Optical Density of the Low-Reflectivity Chrome Obstructions vs. Wavelength
Posted Comments: | |
Ian Oldenburg
 (posted 2023-10-23 16:39:19.78) Can you make these full apperature obstruction targets on a 2inch optic? cdolbashian
 (posted 2023-10-27 04:46:42.0) Thank you for reaching out to us with this inquiry. We indeed can make such an obstruction. I have contacted you directly to gather some more information regarding specifications of your custom. |