학술논문
Improved optoelectronic mixing of InAlAs/InGaAs interdigitated-finger metal-semiconductor-metal photodetectors
Document Type
Conference
Author
Source
Proceedings of IEEE Sensors 2003 (IEEE Cat. No.03CH37498) IEEE Sensors 2003 Sensors, 2003. Proceedings of IEEE. 2:1021-1025 Vol.2 2003
Subject
Language
Abstract
We analyze the optoelectronic mixing characteristics of an InAlAs, Schottky-enhanced, InGaAs-based metal-semiconductor-metal photodetector. We show that the mixing efficiency of this device depends on the thickness of the InAlAs Schottky-enhancement layer: For thick enhancement layers (/spl ap/ 500 /spl Aring/), the bandwidth of the device when utilized as an optoelectronic mixer is less than the bandwidth of the device when utilized as a simple photodetector. In addition, the mixing efficiency depends on the light-modulation, local-oscillator, and mixed-signal frequencies, and decreases nonlinearly with decrease in optical power. For thin enhancement layers (/spl ap/ 100 /spl Aring/), the mixing characteristics improve: The bandwidth of the optoelectronic mixer is similar to that of a corresponding photodetector and the mixing efficiency decreases only slightly with decrease in optical power. We attribute the observed behavior to the band-gap discontinuity associated with the InAlAs Schottky enhancement layer.