Avalanche Photodiode Working Research Articles

APD optimal bias voltage compensation method based on machine learning

The signal-to-noise ratio (SNR) of avalanche photodiode (APD) in optical detection system is greatly influenced by background radiation and operating temperature, so an APD optimal bias voltage compensation method based on machine learning is designed to accurately judge the current laser emission state and APD working state so that dichotomy compensation can be carried out to make APD work in optimal state. By means of cross-verification, the accuracy of judging laser emission state and APD working state is as high as 100% and 99.3% separately, then the number of input variables in the model is reduced appropriately by experiment and the prediction speed of the algorithm is further improved. Finally, road detection application is taken as the experimental background and comparison between the proposed method and the most widely used signal amplitude feedback compensation method is carried out. The results of this study suggest that the proposed APD optimal bias voltage compensation method based on machine learning offers a new and promising approach.

Spectral method for characterization of avalanche photodiode working as single-photon detector

In this Letter, a new method for avalanche photodiode characterization, based on the spectral analysis of the photocurrent produced during an avalanche, is proposed. The theory is developed, and an experimental characterization of an avalanche photodiode working in the Geiger mode with CW laser is performed.

Performance of a scintillating strip detector with G-APD readout

The upgraded KLM detector end cap of Belle II experiment will consist of more than 16 000 scintillating detectors of 0.5–2.8 m long strips. One of possible solutions is presented: a detector of 2800×40×10 mm 3 with light readout via WLS fiber and new solid state photo-detector multi-pixel avalanche photo-diode working in Geiger mode. Concept of the mechanical structure of upgraded KLM detector is given. Properties demonstrating the operation capabilities of such a scintillating detector: MIP registration efficiency, noise pulse rate with respect to expected background rate are demonstrated as well as response distributions in longitudinal and transverse directions. Study of radiation damage of photo-detectors shows that Hamamatsu MPPC can be used in Belle II environment during at least 10 years.

Experimental Discussion on Eye-Safe 1.54 ?m Photon Counting Lidar Using Avalanche Photodiode

A Mie hdar system with an eye-safe wavelength of 1.54 μm was developed and its performance characteristics were experimentally discussed. The wavelength was generated by a Nd:YAG based methane-shifted Raman laser. The collected backscattering light was detected by an InGaAs avalanche photodiode working in photon counting mode at that wavelength. Results of atmospheric observation showed clearly the dynamics of multi-layered cluds up to an altitude of 7 km. The system’s performance was confirmed on the point of signal to noise ratio in both the observation and the simulation. Advantages of the eye-safe 1.54 μm wavelength in lidar atmospheric research and system limitations were discussed. © 2004 The Optical Society of Japan

Analysis of an avalanche photodiode used as an optoelectronic mixer for a frequency modulated continuous wave laser range finder

A heterodyne photodetection method is proposed in order to improve the signal to noise ratio of a frequency-modulated-continuous-wave- (FMCW-) like laser range finder. For this purpose, the non-linearity of the current–voltage characteristic of an avalanche photodiode (APD) is used. The photoelectric current is mixed with a local oscillator (LO) signal inside the APD working as an optoelectronic mixer. The signal from the LO can be injected inside the APD by an optical or an electrical channel, both techniques being compared in this paper. A model of the APD taking into account the thermal effects is then proposed. It is demonstrated that the conversion efficiency of the optoelectronic mixer reaches 0.5 in quasi-darkness conditions. Experimental results are in agreement with the theoretical analysis. The feasibility of an FMCW laser range finder using an APD as an optoelectronic mixer is then shown.

Improvement of the FMCW laser range-finder by an APD working as an optoelectronic mixer

A laser range-finder has been designed for distances from 1 to 20 m with diffusing targets. The measurement principle using a frequency modulation continuous wave technique is first described. Improvement for short distance measurements is then proposed with a new set-up using a delay line and an avalanche photodiode working as an optoelectronic mixer used to obtain a wide-band and a low-noise photoreception.