Y. Sakakibara

Bio: Y. Sakakibara is an academic researcher from Mitsubishi Electric. The author has contributed to research in topics: Laser & Laser diode. The author has an hindex of 9, co-authored 25 publications receiving 189 citations.

High-power 1.3-µm InGaAsP P-substrate buried crescent lasers

Abstract: High performance of newly developed InGaAsP P-substrate buried crescent (PBC) laser diodes is described. It is shown that the PBC laser has superior characteristics to the conventional buried crescent (BC) laser with n-InP substrate. The maximum output power of 140 mW under a CW condition is realized at room temperature. CW light output power of 10 mW up to 110°C is achieved. A maximum CW temperature of 135°C is obtained. Stable CW operations have been confirmed in 70°C 5-mW and 70°C 20-mW aging tests. The reason for the high performance is discussed in relation to the leakage current which flows through the current blocking layers.

1.3μm InGaAsP/InP distributed-feedback P-substrate partially inverted buried-heterostructure laser diode

Abstract: A novel 1.3μm InGaAsP/lnP distributed-feedback buried-heterostructure laser diode on p-type InP substrate has been developed utilising a dopant diffusion technique. The laser has achieved a threshold current as low as 20 mA and high output power of 32 mW under CW and SLM operation.

Position of the degradation and the improved structure for the buried crescent InGaAsP/InP (1.3 μm) lasers

Abstract: We have found a degradation of the buried crescent (BC) InGaAsP/InP lasers that occurs when the p‐n junction plane coincides with the surface exposed in the high‐temperature H2 ambient before the melt contact during the liquid phase epitaxial growth. To eliminate the degradation, we have fabricated a new structure of the BC laser and have obtained stable cw operation at 80 °C.

Shunt current and excess temperature sensitivity of Ith and ηex in 1.3 μm InGaAsP DH lasers

Abstract: Shunt current flowing through p-n-p-n current blocking layers is examined as a possible cause of excess temperature sensitivity of Ith and -ex which is often observed in InGaAsP BC and BH lasers. Under certain conditions, the shunt current reduces the T0 value of Ith from 65 K to 45 K and that of -ex from 130 K to 40 K.

Internal Loss of InGaAsP/InP Buried Crescent (λ=1.3 µm) Laser

Abstract: The temperature dependence of the internal loss α of the InGaAsP/InP buired crescent (λ=1.3 µm) laser is presented in the temperature range 20~80°C. α is about 18 cm-1 and no apparent temperature dependence of α is observed in this temperature range. This indicates that the temperature-sensitive behavior of the threshold current in 1.3 µm laser is not due to the internal loss. The decrease in the external quantum efficiency with increasing temperature is attributed to the decrease in the internal quantum efficiency, which is possibly caused by some leakage current.

Frequency response of 1.3µm InGaAsP high speed semiconductor lasers

Abstract: The frequency response of a group of 1.3 μm InGaAsP vapor-phase-regrown buried heterostructure lasers of various cavity lengths is analyzed by fitting the measured response curves. The dependence of resonant frequency f 0 and damping rate \Gamma on bias power is determined. The differential gain coefficient for InGaAsP is determined as 3.5 \times 10^{-16} cm2. The damping rate is found to be proportional to the square of the resonant frequency with a proportionality factor which is independent of device geometry and facet reflectivity. The existence of such a universal relationship between \Gamma and f 0 and the observed magnitude of the damping rate is explained by the interband relaxation model of nonlinear gain.

Gain-coupled DFB lasers versus index-coupled and phase shifted DFB lasers: a comparison based on spatial hole burning corrected yield

Abstract: A statistical yield analysis is presented for gain- and index-coupled distributed feedback (DFB) laser structures, allowing a comparison of their single longitudinal mode (SLM) yield capabilities. For the yield calculations, the threshold gain difference and the longitudinal spatial hole burning (SHB) are taken into account. By comparing the experimental and theoretical yield of index-coupled DFB lasers, the significance of SHB for correct yield predictions is illustrated. For the purpose of comparison, yield calculations for various lambda /4-shifted DFB lasers (with low facet reflectivities) are presented. The most emphasis, however, is on partly gain-coupled DFB lasers. Estimations of practical gain coupling coefficient values for gain and for loss gratings are discussed. >

Defect engineering of Czochralski single-crystal silicon

Abstract: Modern microelectronic device manufacture requires single-crystal silicon substrates of unprecedented uniformity and purity, As the device feature lengths shrink into the realm of the nanoscale, it is becoming unlikely that the traditional technique of empirical process design and optimization in both crystal growth and wafer processing will suffice for meeting the dynamically evolving specifications. These circumstances are creating more demand for a derailed understanding of the physical mechanisms that dictate the evolution of crystalline silicon microstructure and associated electronic properties. This article describes modeling efforts based on the dynamics of native point defects in silicon during crystal growth, which are aimed at developing comprehensive and robust tools for predicting microdefect distribution as a function of operating conditions. These tools are not developed independently of experimental characterization but rather are designed to take advantage of the very detailed information database available for silicon generated by decades of industrial attention. The bulk of the article is focused on two specific microdefect structures observed in Czochralski crystalline silicon, the oxidation-induced stacking fault ring (OSF-ring) and octahedral voids; the latter is a current limitation on the quality of commercial CZ silicon crystals and the subject of intense research. (C) 2000 Published by Elsevier Science S.A.

Dispersion-induced composite second-order distortion at 1.5 mu m

Abstract: Experimental and theoretical results have shown that the composite second-order (CSO) nonlinearity of 1.5- mu m AM analog laser links is inadvertently affected by the coupling of laser chirp with fiber dispersion in regular single-mode fiber. To counteract the dispersion effect, it is shown that dispersion-shifted fiber can be employed in place of the regular fiber. Other possible ways to reduce distortion are to use lasers with reduced chirp, presumably with a multiquantum-well laser structure, or lasers with well-controlled spatial hole burning. Short fiber spans ( >

The effects of loss and nonradiative recombination on the temperature dependence of threshold current in 1.5-1.6 µm GalnAsP/InP lasers

Abstract: Various factors influencing the temperature dependence of the threshold current of GaInAsP/InP lasers in the wavelength region of 1.5-1.6\mu m were measured in terms of the gain, the loss, the spontaneous emission, and the carrier lifetime. The effects of the intervalence band absorption influence the differential quantum efficiency or the loss, while the nonradiative recombination and the carrier leakage over the heterobarrier influence the carrier lifetime. It is shown from the measured results that both the absorption and the nonradiative components significantly influence the temperature characteristics of threshold current. The rapid increase in the threshold current near room temperature is a reflection of the increase in the intervalence band absorption. The heating effect due to the injection current is also significant. The possible maximum temperature of CW operation is expected to be as high as 150°C with optimized structural parameters.