• ETRI Journal
• /
• v.44 no.1
• /
• pp.169-169
• /
• 2022

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.7
• /
• pp.1386-1392
• /
• 2009

An analysis is presented for super-high-speed optical demodulation by an avalanche photodiode(APD) with electric mixing. A normalized gain is defined to evaluate the performance of the optical mixing detection. Unlike previous work, we include the effect of the nonlinear variation of the APD capacitance with bias voltage as well as the effect of parasitic and amplifier input capacitance. As a results, the normalized gain is dependent on the signal frequency and the frequency difference between the signal and the local oscillator frequency. However, the current through the equivalent resistance of the APD is almost independent of signal frequency. The mixing output is mainly attributed to the nonlinearity of the multiplication factor. We show also that there is an optimal local oscillator voltage at which the normalized gain is maximized for a given avalanche photodiode.

• Journal of Internet Computing and Services
• /
• v.13 no.3
• /
• pp.17-22
• /
• 2012

In this paper, a photoelectric image detection system is proposed using an APD(Avalanche Photodiode) sensor, a LED illuminator, and fiberoptic waveguides. This proposed pinhole detection system can detect the pinholes of 100 micron with the speed rate of 1,000mpm(meter per minute). And detecting performance of image system is improved by the SQL based DB analysis of classifying pinhole's detected location and size using image detection algorithms.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.164-165
• /
• 2001

애벌란치형 광검출기(Avalanche Photodiode; APD)는 내부 이득을 갖고 있어 수신감도가 좋고 고속 동작이 가능하여 광통신에 있어서 매우 중요한 소자이다. 초기에는 공정의 용이성 등으로 인해 Ge을 소재로 하는 APD가 많이 사용되었으나 1.55 $\mu\textrm{m}$ 파장에서 광흡수 특성이 좋지 않고 전자와 정공의 이온화 계수비가 거의 같아 GB Product이 낮으므로 점차 이들 특성이 우수한 InP/InGaAs APD가 사용되었다. InGaAs는 밴드갭은 Ge보다 크지만 직접천이형 밴드구조를 갖기 때문에 1.67 $\mu\textrm{m}$까지 광흡수 특성이 좋고 소수캐리어의 이동도가 높아 고속동작에 유리하다. (중략)

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2011.10a
• /
• pp.115-116
• /
• 2011

• Korean Journal of Optics and Photonics
• /
• v.24 no.1
• /
• pp.1-8
• /
• 2013

In this paper, we report design, fabrication and characterization of the WBRM (Wide Band Receiver Module) for LADAR (LAser Detection And Ranging) application. The WBRM has been designed and fabricated using self-made APD (Avalanche Photodiode) and TIA (Trans-impedance Amplifier). The APD and TIA chips have been integrated on 12-pin TO8 header using self-made ceramic submount and circuit. The WBRM module showed 450 ps of rise time, and corresponding 780 MHz bandwidth. Furthermore, it showed very low output noise less than 0.8 mV, and higher SNR than 15 for 150 nW of MDS(Minimum Detectable Signal). To the author's knowledge, this is the best performance of an optical receiver module for LIDAR fabricated by 200 um InGaAs APD.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07b
• /
• pp.1022-1025
• /
• 2002

This paper presents the reliability of planar InP/InGaAs avalanche photodiodes (APD's) with recess etching, which is very crucial for the commercial 10-Gb/s optical receiver application. A versatile design for the planar InP/InGaAs APD's and bias-temperature tests to evaluate long-term reliability at temperature from 200 to $250^{\circ}C$. The reliability is examined by accelerated life tests by monitoring dark current and breakdown voltage. The lifetime of the APD's is estimated by a degradation activation energy. Based on the test results, it is concluded that the planar InP/InGaAs APD's with recess etching shows the sufficient reliability for practical 10-Gb/s optical receivers.

• ETRI Journal
• /
• v.43 no.5
• /
• pp.916-922
• /
• 2021

We calculated the correlation between the doping concentration of the charge layer and the multiplication layer for separate absorption, grading, charge, and multiplication InGaAs/InAlAs avalanche photodiodes (APDs). For this purpose, a predictable program was developed according to the concentration and thickness of the charge layer and the multiplication layer. We also optimized the design, fabrication, and characteristics of an APD for 20 Gbps application. The punch-through voltage and breakdown voltage of the fabricated device were 10 V and 33 V, respectively, and it was confirmed that these almost matched the designed values. The 3-dB bandwidth of the APD was 10.4 GHz, and the bit rate was approximately 20.8 Gbps.

• Proceedings of the Optical Society of Korea Conference
• /
• 2007.07a
• /
• pp.261-262
• /
• 2007

• Korean Journal of Optics and Photonics
• /
• v.7 no.4
• /
• pp.440-444
• /
• 1996

In this paper, we report an InGaAs/InAlAs multi-quantum well (MQW) avalanche photodiode (APD) showing a performance suitable for 10 Gbps lightwave communications. In designing the device, emphasis is given on the effect of indiffusion of Be dopant from the highly doped field layer into the MQW multiplication region. It is found that a small amount of diffusion can alter the dark current and gain characteristics of the device significantly. A spacer used to restrain such indiffusion is shown effective in reducing dark current (500 nA at a gain of 10) while maintaining a high bandwidth (10 GHz at a gain of 10) devices grown by molecular beam epitaxy.