Adaptive focal plane array (AFPA) technologies for integrated infrared microsystems

P. Mitra; J. D. Beck; M. R. Skokan; J. E. Robinson; J. Antoszewski; K. J. Winchester; A. J. Keating; T. Nguyen; K. K. M. B. D. Silva; C. A. Musca; J. M. Dell; L. Faraone

doi:10.1117/12.673010

18 May 2006 Adaptive focal plane array (AFPA) technologies for integrated infrared microsystems

P. Mitra, J. D. Beck, M. R. Skokan, J. E. Robinson, J. Antoszewski, K. J. Winchester, A. J. Keating, T. Nguyen, K. K. M. B. D. Silva, C. A. Musca, J. M. Dell, L. Faraone

Author Affiliations +

Proceedings Volume 6232, Intelligent Integrated Microsystems; 62320G (2006) https://doi.org/10.1117/12.673010
Event: Defense and Security Symposium, 2006, Orlando (Kissimmee), Florida, United States

Abstract

Hyperspectral imaging in the infrared bands is traditionally performed using a broad spectral response focal plane array, integrated in a grating or a Fourier transform spectrometer. This paper describes an approach for miniaturizing a hyperspectral detection system on a chip by integrating a Micro-Electro-Mechanical-System (MEMS) based tunable Fabry Perot (FP) filter directly on a photodetector. A readout integrated circuit (ROIC) serves to both integrate the detector signal as well as to electrically tune the filter across the wavelength band. We report the first such demonstration of a tunable MEMS filter monolithically integrated on a HgCdTe detector. The filter structures, designed for operation in the 1.6-2.5 μm wavelength band, were fabricated directly on HgCdTe detectors, both in photoconducting and high density vertically integrated photodiode (HDVIP) detectors. The HDVIP detectors have an architecture that permits operation in the standard photodiode mode at low bias voltages (≤0.5V) or in the electron avalanche photodiode (EAPD) mode with gain at bias voltages of ~20V. In the APD mode gain values of 100 may be achieved at 20 V at 200 K. The FP filter consists of distributed Bragg mirrors formed of Ge-SiO-Ge, a sacrificial spacer layer within the cavity and a silicon nitride spacer membrane for support. Mirror stacks fabricated on silicon, identical to the structures that will form the optical cavity, have been characterized to determine the optimum filter characteristics. The measured full width at half maximum (FWHM) was 34 nm at the center wavelength of 1780 nm with an extinction ratio of 36.6. Fully integrated filters on HgCdTe photoconductors with a center wavelength of approximately 1950 nm give a FWHM of approximately 100 nm, and a peak responsivity of approximately 8×10⁴ V/W. Initial results for the filters on HDVIP detectors exhibit FWHM of 140 nm.

Citation Download Citation

P. Mitra, J. D. Beck, M. R. Skokan, J. E. Robinson, J. Antoszewski, K. J. Winchester, A. J. Keating, T. Nguyen, K. K. M. B. D. Silva, C. A. Musca, J. M. Dell, and L. Faraone "Adaptive focal plane array (AFPA) technologies for integrated infrared microsystems", Proc. SPIE 6232, Intelligent Integrated Microsystems, 62320G (18 May 2006); https://doi.org/10.1117/12.673010

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available