Frequency response of avalanche photodetectors with separate absorption and multiplication layers (original) (raw)

Avalanche Photodiodes with Dual Multiplication Layers for High-Speed and Wide Dynamic Range Performances

Photonics

In this work, we demonstrate In0.52Al0.48As top/backside-illuminated avalanche photodiodes (APD) with dual multiplication layers for high-speed and wide dynamic range performances. Our fabricated top-illuminated APDs, with a partially depleted p-type In0.53Ga0.47As absorber layer and thin In0.52Al0.48As dual multiplication (M-) layer (60 and 88 nm), exhibit a wide optical-to-electrical bandwidth (16 GHz) with high responsivity (2.5 A/W) under strong light illumination (around 1 mW). The measured bias dependent 3-dB O-E bandwidth was pinned at 16 GHz without any serious degradation near the saturation current output. To further increase the speed, we downscaled the active diameter and adopted a back-side illuminated structure with flip-chip bonding for batter optical alignment tolerance. A significant improvement in maximum bandwidth was demonstrated (25 versus 18 GHz). On the other hand, we adopted a thick dual M-layer (200 and 300 nm) and 2 μm absorber layer in the APD design to ci...

Effect of Multiplication and Absorption Layers Width on Avalanche Multiplication Gain in InGaAs/InP Avalanche Photodiode

International Journal of Engineering & Technology

The separate absorption, grading, charge, and multiplication (SAGCM) InGaAs/InP avalanche photodiodes (ADPs) are widely used in long distance, high bit rate optical communication system due to their high performance and response to optical fiber wavelength spectrum. In this work, the effect of multiplication layer width (MLW) and absorption layer width (ALW) on APD performance is studied and investigated. Silvaco TCAD software is used as simulation tools to simulate a precise model of InGaAs/InP APD and analyze its, performance under an illuminated condition. As such, three different ALW with various MLW has been simulated while the structure values and material parameters are kept constant. It was found that in the APD with smaller MLW, the distance between the punch-through voltage and the breakdown voltage can be maximized. Therefore, the operation region of APD will be extended. In addition, the multiplication gain is obtained from the photocurrent and primary current by taking ...