Optimization of 10-Gb/s long-wavelength floating guard ring InGaAs-InP avalanche photodiodes

We demonstrate long-wavelength (/spl lambda/ = 1.3 and 1.5 μm) high-speed (10 Gb/s) InGaAs-InP separate absorption-grading-and-multiplication region avalanche photodiodes (SAGM-APDs) employing a double diffused floating guard ring (FGR) structure to eliminate edge breakdown. The simple /spl ges/ 60-GHz gain-bandwidth product double diffused FGR structure was optimized using theoretical and experimental studies. The APD excess noise factor was measured, and suggests that dead-length effects must be considered in designing high bandwidth devices with thin multiplication layers.