Han Sung Joo

Yonsei University, Sŏul, Seoul, South Korea

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Publications (4)2.73 Total impact

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    Han Sung Joo · Sang-Wan Ryu · Jeha Kim · Ilgu Yun
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    ABSTRACT: This paper presents the experimental observation of the degradation in asymmetric sampled grating DFB lasers by the accelerated life tests. Two degradation phenomena related to the electrical characteristics of LDs are observed during the tests. The first degradation phenomenon by increasing the reverse current is considered as a formation of leakage current path enough to prevent lasing operation in lateral blocking layer near active region of lasers. The second degradation phenomenon by decreasing the forward current is considered as activation of non-radiative Auger recombination process by thermal energy. It is also experimentally observed that the second degradation phenomenon is recovered after remained in room temperature with no electrical stress. Therefore, the criteria for LD reliability can be determined by observing the degradation of the reverse current–voltage characteristics.
    Full-text · Article · Jun 2007 · Microelectronics Journal
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    ABSTRACT: The reliability of 1.55-μm wavelength InGaAs waveguide photodiodes (WGPDs) fabricated by metal-organic chemical vapor deposition is investigated for 40-Gb/s optical receiver applications. Reliability for both high-temperature storage and accelerated life tests obtained by monitoring both the dark current and the breakdown voltage is examined. The median device lifetime and the activation energy of the degradation mechanism are extracted for WGPD test structures. The device lifetimes are examined via statistical analysis which is highly reliable in predicting the device lifetime under practical conditions. The degradation mechanism for the WGPD test structures can be explained by the formation of leakage current path by ionic impurities in the passivation layer on the exposed p-n junction. Nevertheless, it can be concluded that the WGPD test structures exhibit sufficient reliability for practical 40-Gb/s optical receiver applications.
    Preview · Article · Jul 2005 · IEEE Transactions on Device and Materials Reliability
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    ABSTRACT: As a summary, the reliability testing of mesa InGaAs WGPDs from the viewpoint of evaluation long-term reliability has been investigated using the accelerated life tests. From the reliability testing results, it was found that the WGPD structure yielded devices that exhibited the median lifetime of much longer than 106 h at practical use conditions. Consequently, this WGPD structure has sufficient characteristics for practical 40-Gb/s optical receiver modules.
    No preview · Conference Paper · Aug 2004
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    ABSTRACT: With the need of high-speed and mass data transmission, optical communication system requires the growth of optical components. Waveguide photodiodes (WGPDs) are introduced and the circuit models of the WGPD and the WGPD submodule are required for the optical receiver application. In this paper, the circuit models of the WPGD and the WGPD submodule are investigated using the partial element equivalent circuit (PEEC) methodology by optimizing the measured S-parameters. In addition, the optical to electrical (O/E) conversion characteristics of the WGPD and the WGPD submodule are examined with the established WGPD models. The physical variation of the WGPD in the presence of optical source is also examined.
    Full-text · Conference Paper · Feb 2004