Related Experiment Video
Updated: May 12, 2026
07:14
Microfabrication of Implantable Optics Integrated in a Microstructured Imaging Window for Advanced In Vivo Imaging
Published on: April 11, 2025
Micromachined silicon grisms for infrared optics
Douglas J Mar1, Jasmina P Marsh, Casey P Deen
1Liquidia Technologies, Inc., North Carolina, USA; Department of Astronomy, The University of Texas at Austin, Austin Texas, USA.
Applied Optics
|April 10, 2013
Summary
We developed large silicon gratings for infrared grisms, achieving high diffraction efficiency and precise groove control. These advanced optical components offer excellent performance for astronomical spectroscopy.
Area of Science:
- Optics and Photonics
- Materials Science
- Infrared Astronomy
Background:
- Silicon is a key material for infrared optics due to its high refractive index.
- Developing large-format gratings with precise control is crucial for advanced spectroscopic instruments.
Purpose of the Study:
- To fabricate large-format silicon gratings for high-efficiency infrared grism applications.
- To evaluate the optical performance and diffraction efficiency of these novel gratings.
Main Methods:
- Microlithography and chemical wet etching techniques were employed for grating fabrication.
- Profilometric measurements were used to verify the physical dimensions and groove structure.
- Optical performance was assessed through diffraction efficiency measurements and wave surface error analysis.
Main Results:
- Successfully fabricated large (50 mm × 50 mm) silicon gratings with controlled blaze angles and excellent groove quality.
- Achieved peak diffraction efficiencies of 70-95% of theoretical maximum in reflection.
- Demonstrated transmission efficiencies of 30-48% (uncorrected) in the near-infrared, exceeding diffraction-limited performance specifications.
Conclusions:
- The fabricated silicon gratings are suitable for high-efficiency infrared grism applications.
- These gratings enable high-resolution, high-order dispersion in compact optical designs.
- The technology is being applied to enhance spectroscopic capabilities of mid-infrared cameras like FORCAST.
