Time resolved gain and excess noise properties of InGaAs/InAlAs avalanche photodiodes with cascaded discrete gain layer multiplication regions

Abstract

To predict pulse detection performance when implemented in high speed photoreceivers, temporally resolved measurements of a 10-stage InAlAs/InGaAs single carrier multiplication (SCM) avalanche photodiode (APD)'s avalanche response to short multi-photon laser pulses were explained using instantaneous (time resolved) pulse height statistics of the device's impulse response. Numeric models of the junction carrier populations as a function of the time following injection of a primary photo-electron were used to create the probability density functions (pdfs) of the instances of the avalanche buildup process. The numeric pdfs were used to generate low frequency gain and excess noise models, which were in good agreement with analytic models of multiple discrete low-gain-stage APDs and with measured excess noise data. The numeric models were then used to generate the instantaneous and cumulative instantaneous low order statistics of the instances of the impulse response. It is shown that during the early times of the impulse response, the SCM APDs have lower excess noise than the pseudo-DC measurements and the common APDmodels used to describe them. The methods of determining the time resolved low order statistics of APDs are described and the importance of using time-resolved models of APDgain and noise is discussed.

Non-Local Model for the Spatial Distribution of Impact Ionization Events in Avalanche Photodiodes

“…We have calculated the spatial distribution of electron-and hole-ionization events for two different cases of the multiplication region: (i) a hole-injection InP homojunction multiplication region, and (ii) an InAlAs/InAlGaAs electron-injection heterojunction multiplication region based on the multi-stage multiplication region reported in [10](See Fig. 1 in [10]).…”

“…We have also calculated the spatial distribution of the electron-and hole-impact ionization events considering a single-carrier multiplication (SCM) APD with an InAlAs/InAlGaAs multiplication region. SCM-APDs were developed by Voxtel Inc. to obtain quasi-deterministic multiplication gains by suppressing hole impact ionization events [7], [10]. The multiplication region of an SCM-APD consists of a cascaded multiplier architecture, which combines various design techniques to suppress hole ionizations and enhance electron ionizations [7], [10].…”

Multi-Gain-Stage InGaAs Avalanche Photodiode With Enhanced Gain and Reduced Excess Noise

“…The combination of a strong electric field and a lower impactionization threshold energy in layer (ii) promotes impactionization by hot electrons injected from layer (i), but the layer is designed to be too thin for the cold holes injected from the energy relaxation layer (labeled "iii") to pick up sufficient energy to ionize. Finally, layer (iii), is characterized by an electric field sufficiently low that individual hole carriers spend very little time with kinetic energy in excess of the ionization threshold; this suppresses the probability of hole ionization, so that low noise avalanche multiplication is achieved [30].…”

“…The multi-stage single carrier multiplication (SCM) APD was developed for low noise, high gain operation [30]. The SCM APD applies the traditional I 2 E techniques of dead-space and alloy selection with tailoring of the electric field profile to modulate impact ionization probability.…”

Optimization of eyesafe avalanche photodiode lidar for automobile safety and autonomous navigation systems

“…The most common InGaAs APDs have bulk InP multipliers characterized by k ¼ 0.4. InGaAs APDs with thin InAlAs multipliers are characterized by k < 0.2, and Voxtel, Inc., has developed InGaAs APDs with multiple gain stages that can operate with k~0.02 17 Most InGaAs APDs generate the majority of their primary dark current in their absorber, alongside the primary photocurrent generated by the optical signal and the background signals. In that case, dark carriers from primary dark current can be grouped with the background, as follows: E Q -T A R G E T ; t e m p : i n t r a l i n k -; e 0 0 7 ; 3 2 6 ; 7 1 9…”