We have developed a diffractive micromachined chopper (DMC) for an IR wavelength of ∼10 μm. This device operates mechanically by movable reflection grating beams. It modulates the diffraction efficiency by controlling the displacement of grating beams by an electrostatic force. For a CO2 laser beam, a high modulation efficiency of 84% with an -0.8-dB small insertion loss was obtained by detecting 0th-order diffracted light. A novel pyroelectric IR microsensor with a DMC and a diffractive multilevel Si microlens was proposed and it demonstrated the detection of human existence.
© 1998 Optical Society of America
Original Manuscript: June 10, 1997
Revised Manuscript: October 8, 1997
Published: March 1, 1998
Michihito Ueda, Teruhiro Shiono, Tatsuo Ito, and Kazuo Yokoyama, "High-efficiency diffractive micromachined chopper for infrared wavelength and its application to a pyroelectric infrared sensor," Appl. Opt. 37, 1165-1170 (1998)