Optical signal distribution to MSM photodetector arrays via integrated polyimide waveguides

• Published in: Journal of lightwave technology Vol. 15; no. 9; pp. 1700 - 1707
• Main Authors: Callender, C.L., Robitaille, L., Noad, J.P., Gouin, F., Almeida, C.A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-09-1997; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; Coatings; Detectors; Electric, optical and optoelectronic circuits; Electrodes; Electronics; Exact sciences and technology; Gallium arsenide; Indium tin oxide; Integrated optoelectronics. Optoelectronic circuits; Optical and optoelectronic circuits; Optical arrays; Optical buffering; Optical waveguides; Photodetectors; Polyimides; Polyimide; Microelectronic fabrication; Optoelectronics; Ridge waveguide; Optical properties; Performance characteristic; Optical waveguide; MSM structure; Photodetector
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/50.622897

The integration of metal-semiconductor-metal (MSM) photodetector arrays with polyimide ridge waveguides is demonstrated. MSM detectors were fabricated using transparent indium tin oxide (ITO) interdigitated electrodes on semi-insulating GaAs substrates. An optical buffer layer of SiO/sub 2/ was deposited and patterned, and then polyimide ridge waveguides were fabricated on top by spin coating and photolithography. The guides were multimode with widths from 10 to 50 /spl mu/m. Light at 830 nm was coupled efficiently from the waveguides through gaps in the SiO/sub 2/ buffer layer into the underlying detector structures. Absolute responsivities of the integrated MSM devices were around 0.5 A/W and the 3 dB bandwidths of 5-6 GHz were measured. Division of the input signal between sets of two and four detectors under a single waveguide has been achieved, highlighting the potential for the fabrication of integrated optoelectronic switches.