HIGH GAIN BANDWIDTH PRODUCT OVER 140-GHZ PLANAR JUNCTION ALINAS AVALANCHE PHOTODIODES

This letter demonstrates a planar junction GalnAs-AlInAs avalanche photodiode using back-side illumination through thinned InP substrate covered with chemical vapor deposition SiNx antireflection coating. The combined properties of very low dark current (Idark(M = 0) = 17 nA), low excess noise factor (f(M = 10) = 3.5), and high gain x bandwidth product over 140 GHz were simultaneously achieved with a high primary responsivity of 0.95 A/W at 1.55 mum.