Fabrication and testing of a silicon immersion grating for infrared spectroscopy

Conference · Mon Jul 25 00:00:00 EDT 1994

OSTI ID:10175614

Kuzmenko, P J; Ciarlo, D R; Stevens, C G

Recent advances in silicon micromachining techniques (e.g. anisotropic etching) allow the fabrication of very coarse infrared echelle gratings. When used in immersion mode, the dispersion is increased proportionally to the refractive index. This permits a very significant reduction in the overall size of a spectrometer while maintaining the same resolution. We have fabricated a right triangular prism (30{times}60{times}67 mm with a rectangular entrance face 30{times}38 mm) from silicon with a grating etched into the face of the hypotenuse. The grating covers an area of 32 mm by 64 mm and has a 97.5 PM periodicity with a blaze angle of 63.4{sup o}. The groove surfaces are very smooth with a roughness of a few manometers. Random defects in the silicon are the dominant source of grating scatter ({approx} 12% at 3.39 {mu}m). We measure a grating ghost intensity of 1.2%. The diffraction peak is quite narrow, slightly larger than the Airy disc diameter at F/12. However due to wavefront aberrations, perhaps 15--20% of the diffracted power is in the peak with the rest distributed in a diameter roughly five times the Airy disc.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 10175614
• Report Number(s): UCRL-JC-117810; CONF-940723-15; ON: DE94017173
• Resource Relation: Conference: Annual meeting of the Society of Photo-Optical Instrumentation Engineers,San Diego, CA (United States),24-29 Jul 1994; Other Information: PBD: 25 Jul 1994
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
54 ENVIRONMENTAL SCIENCES
47 OTHER INSTRUMENTATION
GRATINGS
FABRICATION
DIFFRACTION GRATINGS
INFRARED SPECTROMETERS
SILICON
REMOTE SENSING
ATMOSPHERIC CHEMISTRY
400102
540120
440800
CHEMICAL AND SPECTRAL PROCEDURES
CHEMICALS MONITORING AND TRANSPORT
MISCELLANEOUS INSTRUMENTATION