The present disclosure relates to a semiconductor light emitting device, comprising: a plurality of semiconductor layers, including a first semiconductor layer having a first conductivity, a second semiconductor layer having a second conductivity different from the first conductivity, and an active layer interposed between the first semiconductor layer and the second semiconductor layer, generating light via electron-hole recombination; a first electrode, supplying either electrons or holes to the plurality of semiconductor layers; a second electrode, supplying, to the plurality of semiconductor layers, electrons if the holes are supplied by the first electrode, or holes if the electrons are supplied by the first electrode; a non-conductive distributed bragg reflector coupled to the plurality of semiconductor layers, reflecting the light from the active layer; and a first light-transmitting film coupled to the distributed bragg reflector from a side opposite to the plurality of semiconductor layers with respect to the non-conductive distributed bragg reflector, with the first light-transmitting film having a refractive index lower than an effective refractive index of the distributed bragg reflector.

Semiconductor Light Emitting Device

Injection locking of AlGaAs double-heterostructure (DH) lasers was studied with respect to locking bandwidth, required power, and coherence. The relation of the locking bandwidth versus the ratio of locked laser power to injected power was consistent with the classical analysis on injection locking phenomena reported by Adler [2]. The measured maximum locking bandwidth was 5.8 GHz when the locking gain was 18 dB. A maximum gain of 40 dB was observed with a 500 MHz locking bandwidth. The power increase in the injected mode agrees well with theoretical values calculated with the van der Pol equation. The interference pattern was observed between an injecting beam and a locked laser beam. Visibility was the same as that obtained by the interference between forward and backward emitted beams in an identical free-running laser. Spurious mode suppression was observed when a single-frequency optical power is injected into an RF-modulated laser. Single longitudinal mode operation was obtained at a sufficiently high injecting level.

Injection locking in AlGaAs semiconductor laser

Refractive indices and absorption coefficients of In1−x Gax P1−yAsy for y = 0 to 1 lattice matched to InP and of GaAs and GaP have been measured by ellipsometry in the wavelength range between 365 and 1100 nm. The high‐purity layers (7×1014<n<2×1016 cm−3) used here were grown by liquid phase epitaxy. The quaternary refractive indices were also calculated from the measured indices of the constituent binary compounds by averaging the quantity (e−1)/(e+2). The e values were all taken at the same energy separation from the respective band gaps. The results of this new averaging procedure are compared with the measured indices and with the refractive index steps to InP deduced from lasers. In addition, the absorption coefficient of InP near the band gap was measured as a function of the doping level. Finally, the temporal growth of the natural oxide layer thickness dox on various InP and GaAs samples was determined by ellipsometry. For InP, the increase of dox is 0.39 nm per decade of time.

Optical properties of In1−xGaxP1−yAsy, InP, GaAs, and GaP determined by ellipsometry

A new high-performance 1.3-μm InGaAsP semiconductor laser is described, in which effective current confinement into the active region has been realized. A p-n-p-n current blocking structure is made by liquid-phase epitaxy (LPE) on both sides of the active-stripe mesa which is defined by a pair of channels in the double-heterostructure wafer. The double-channel-planar-buried-heterostructure laser diodes (DC-PBH LD's) exhibit high-laser performances, such as a high differential quantum efficiency of 78-percent maximum, which results in high electrical to optical power conversion efficiency 43 percent, and high light output power of over 50 mW, as a result of the improvement in the current blocking structure. The threshold current temperature sensitivity is found experimentally to be reduced remarkably by increasing the doping concentration in the p-cladding layer. Characteristic temperature as high as 100 K has been obtained. CW operation is possible up to 130°C.

InGaAsP double-channel- planar-buried-heterostructure laser diode (DC-PBH LD) with effective current confinement

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.

Defect engineering of Czochralski single-crystal silicon

An InGaAsP/InP laser diode emitting at 1.3 μm with a crescent shaped active region is described. The active region is completely embedded in InP by a two-step LPE technique, and a double current confinement scheme is incorporated with two reverse biased p-n junctions at both sides of the active layer. A threshold current as low as 20 mA has been achieved in CW operation at room temperature. Fundamental transverse mode operation with linear light output-current characteristics and single longitudinal mode oscillation have been obtained.

Low threshold InGaAsP/InP buried crescent laser with double current confinement structure

An InGaAsP/InP injection laser is described in which a crescent-shaped InGaAsP active region is completely embedded in InP by the etch-and-fill l.p.c. technique and a double current confinement scheme is incorporated with two reverse-biased p-n junctions on both sides of the active layer. The best laser has the very low threshold current of 28 mA c.w. at room temperature, and shows stable single-mode c.w. operation up to about twice the threshold current.

InGaAsP/InP buried crescent laser emitting at 1.3 μm with very low threshold current

The fabrication procedure, designing of an active region and a p-n-p-n current blocking structure, characteristics and the aging results of an InGaAsP/InP buried crescent (BC) laser diode are described. The BC laser diodes exhibit high laser performances, such as a low-threshold current, a fundamental transverse mode oscillation with linear light output-current characteristics. CW operation at as high as 100°C is achieved with a junction up configuration as a result of the improvement in the current blocking structure. A stable CW operation at 80°C has been realized with a constant optical output power of 5 mW.

InGaAsP/InP buried crescent laser diode emitting at 1.3 &#181;m wavelength

Transverse mode stabilisation of InGaAsP/InP buried crescent laser diodes emitting at 1.3 ?m is described. Width and thickness of the active region have been reduced to stabilise the transverse mode. Operation up to 17 mW/facet in a stable transverse mode and threshold current as low as 12 mA in CW operation have been obtained.

Transverse mode control in InGaAsP/InP buried crescent diode lasers

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.

E. Oomura

Papers

Low threshold InGaAsP/InP buried crescent laser with double current confinement structure

InGaAsP/InP buried crescent laser emitting at 1.3 μm with very low threshold current

InGaAsP/InP buried crescent laser diode emitting at 1.3 µm wavelength

Transverse mode control in InGaAsP/InP buried crescent diode lasers

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

E. Oomura

Papers

Low threshold InGaAsP/InP buried crescent laser with double current confinement structure

InGaAsP/InP buried crescent laser emitting at 1.3 μm with very low threshold current

InGaAsP/InP buried crescent laser diode emitting at 1.3 &#181;m wavelength

Transverse mode control in InGaAsP/InP buried crescent diode lasers

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

InGaAsP/InP buried crescent laser diode emitting at 1.3 µm wavelength