Abstract :
The two main trends in the progress of ultrawide-band/high-frequency photodetectors (PD´s), improving the bandwidth-efficiency product and obtaining a high saturation current, are reviewed. With respect to achieving large bandwidth-efficiency, the limiting factors and potentials of edge-coupled (waveguide, waveguide-fed, traveling-wave, periodic-traveling-wave), resonant-cavity, and refracting-facet photodiodes, as well as the avalanche photodiode are discussed. Regarding high-saturation current, the author estimated how much the space-charge effect limits the saturation current and two ways to reduce the space-charge effect are outlined. One way is to distribute the photocarriers along the edge-coupled PD´s and the other is to increase the carrier velocity using a uni-traveling carrier structure. The waveguide-photodiode-based technologies that we have developed are also presented; namely the design and fabrication of a 100-GHz waveguide photodiode (WGPD), uni-traveling carrier WGPD, 60-GHz packaging, and a 20-GHz large-core WGPD for planar lightwave circuit integration. A 50-Gb/s receiver opto-electronic integrated circuit technology based on the WGPD is also presented
Keywords :
avalanche photodiodes; integrated circuit technology; integrated optoelectronics; microwave photonics; optical receivers; optical waveguides; photodetectors; photodiodes; reviews; semiconductor device packaging; space charge; 20 to 100 GHz; 50 Gbit/s; APD; MM-wave packaging; avalanche photodiode; bandwidth-efficiency product; carrier velocity; edge-coupled photodiodes; high saturation current; high-frequency photodetectors; large-core waveguide PD; opto-electronic integrated circuit; planar lightwave circuit integration; receiver OEIC technology; refracting-facet photodiodes; resonant-cavity photodiodes; space-charge effect; ultrawide-band photodetectors; uni-traveling carrier structure; waveguide photodiode; waveguide-photodiode-based technologies; Avalanche photodiodes; Bandwidth; Integrated circuit technology; Optical receivers; Optical refraction; Optical saturation; Optical waveguides; Photodetectors; Planar waveguides; Resonance;
