• Journal of the Optical Society of Korea
• /
• v.12 no.4
• /
• pp.217-220
• /
• 2008

An optical receiver using a CMOS-compatible avalanche photodetector (CMOS-APD) is demonstrated. The CMOS-APD is fabricated with $0.18{\mu}m$ standard CMOS technology and the optical receiver is implemented by using the CMOS-APD and a transimpedance amplifier on a board. The optical receiver can detect 6.25-Gb/s data with the help of the series inductive peaking effect.

• Journal of the Optical Society of Korea
• /
• v.15 no.1
• /
• pp.1-3
• /
• 2011

We characterize and analyze silicon avalanche photodetectors (APDs) fabricated with standard complementary metal-oxide-semiconductor (CMOS) technology. Current characteristics, responsivity, avalanche gain, and photodetection bandwidth of CMOS-APDs based on two types of PN junctions, N-well/P-substrate and $P^+$/N-well junctions, are compared and analyzed. It is demonstrated that the CMOS-APD using the $P^+$/N-well junction has higher responsivity as well as higher photodetection bandwidth than N-well/P-substrate. In addition, the important factors influencing CMOS-APD performance are clarified from this investigation.

• Current Optics and Photonics
• /
• v.4 no.4
• /
• pp.273-276
• /
• 2020

We report on the relationship between output current for quadrant photodetector (QPD) and bias voltage in silicon-based p-i-n (positive-intrinsic-negative) QPD examined using millisecond pulse laser (ms pulse laser) irradiation. The mechanism governing the relationship was further studied experimentally. The output current curves were obtained by carrying out QPD under different bias voltages (0-40 V) irradiated by ms pulse laser. Compared to other photodetectors, the relaxation was created in the output current for QPD which is never present in other photodetectors, such as PIN and avalanche photodetector (APD), and the maximum value of relaxation was from 6.8 to 38.0 ㎂, the amplitude of relaxation increases with bias value. The mechanism behind this relaxation phenomenon can be ascribed to the bias voltage induced Joule heating effect. With bias voltage increasing, the temperature in a QPD device will increase accordingly, which makes carriers in a QPD move more dramatically, and thus leads to the formation of such relaxation.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2312-2314
• /
• 2005

For the upcoming nano-bio technology(NBT), we suggested InAs self-assembled quantum dot enhanced resonant-cavity avalanche type photodetector to detect near infrared(NIR) wavelength. To confirm the feasibility of RC-APD structure, we have simulated using conventional simulator.

• The Journal of Korea Robotics Society
• /
• v.13 no.4
• /
• pp.230-236
• /
• 2018

3D depth perception has played an important role in robotics, and many sensory methods have also proposed for it. As a photodetector for 3D sensing, single photon avalanche diode (SPAD) is suggested due to sensitivity and accuracy. We have researched for applying a SPAD chip in our fusion system of time-of-fight (ToF) sensor and stereo camera. Our goal is to upsample of SPAD resolution using RGB stereo camera. Currently, we have 64 x 32 resolution SPAD ToF Sensor, even though there are higher resolution depth sensors such as Kinect V2 and Cube-Eye. This may be a weak point of our system, however we exploit this gap using a transition of idea. A convolution neural network (CNN) is designed to upsample our low resolution depth map using the data of the higher resolution depth as label data. Then, the upsampled depth data using CNN and stereo camera depth data are fused using semi-global matching (SGM) algorithm. We proposed simplified fusion method created for the embedded system.