S. M. Mitani

Optimization of electro-optical characteristics of GaAs-based oxide confinement VCSEL

An experimental study has been presented of the oxide-confined vertical-cavity surface-emitting lasers (VCSEL) operating in the 850 nm region of the electromagnetic spectrum. In this regard, various relevant VCSEL samples with numerous oxide aperture sizes have been fabricated and characterized. Thorough investigations of the electrical as well as optical characteristics of the fabricated samples have been performed which includes the overall device performance as a function of the oxidize aperture sizes. It is reported that the VCSEL with oxide aperture size <10 μm require low threshold currents (<1 mA). Further, the differential quantum efficiencies up to 28% were measured for a number of these devices. It is found that devices employing oxide aperture of 10 to 15 μm shows promising electro-optical characteristics for 850 nm oxide VCSEL optimization.

Improved efficiency of GaAs-based VCSEL by utilizing fan-pad metallization and trench patterning

Emphasizing the Vertical-Cavity Surface-Emitting Laser (VCSEL) device packaging, fan-pad metallization and trench patterning are demonstrated for VCSEL operating at 850 nm of the electromagnetic spectrum. The fabricated devices are observed to exhibit low threshold current and series resistance, contributing thereby to higher VCSEL efficiency. It is also observed that the output spectral characteristics of the fabricated device show stable multimode operation. The results indicate that the proposed VCSEL packaging exhibits superior device performance as compared to the VCSEL device packaged with square-pad metal.

Electro-Opto Characteristics of 850 nm Oxide-Confined Vertical-Cavity Surface-Emitting Lasers

In this paper, an MOCVD grown of VCSEL with an operating wavelength of 850 nm is fabricated and characterized. The sample includes numerous oxide aperture sizes, allowing a thorough investigation of the electrical and optical characteristics and overall device performance. Low threshold current operation <1mA was achieved for oxide apertures smaller than 10 mum. Analysis of the VCSEL performance as a function of the oxidize aperture sizes is also reported.

Simulation of a New Type of Oxide Confined 850 nm VCSEL

The VCSEL design presented in this paper can suitably be operated in the 850 nm region of the electromagnetic spectrum. The reflection mirrors are made of AlGaAs layers. A better confinement of light is achieved by the introduction of an oxide confinement layer. PIC3D software is used to finally obtain various relevant results that greatly affect the performance of the device; the paper reports a few of them

A Novel Design and Characterization of Oxide Confined 850 nm VCSEL

The present communication reports an investigation of a new kind of VCSEL with the operating wavelength at 850 nm of the electromagnetic spectrum. The efficacy of the device lies in that the oxide layer is introduced in order to achieve a better confinement of light in the central portion of the device. Further, the introduction of the low-doped DBR layers near the spacers, and the barrier reduction layers in the DBRs finally present much better efficiency of the device. Simulations have been performed for the analyses of several features of the proposed VCSEL in respect of the different controlling parameters for the device, e.g. the intensity, power and current distributions, gain response, output intensity profile, slope efficiency etc

Design and fabrication of power-efficient VCSEL-based optical transceiver

This communication presents an analysis of the design and fabrication of power-efficient, low cost VCSEL-based optical transceiver proposed for emerging fiber data distributed interface (FDDI) and fiber channel local-area network (FCLANpsilas). This transceiver has been designed to meet the increasing amount of information transmitted through communication networks. The proposed optical transceiver consists of Tx that contains VCSEL driver and power control units and Rx that contains trans-impedance amplifier, limiting amplifier as well as automatic gain control. The most important reason to lower the power consumption of optical transceivers is to alleviate the increasing heat dissipation associated with denser opto-electronic (OE) devices. VCSEL devices operating at low temperature display decrease jitter, increase output power and enhance lifetime. Also, temperature gradient on large opto-electronic (OE) device arrays generates performance non-uniformities and lowers the bit-error-rate (BER) of the optical links. In addition, lowering the power consumption of optical transceivers contribute to the overall reduction of the system power budget.

Design and fabrication of long-wavelength GaInNAs quantum well edge-emitting lasers

The paper presented comprehensive theoretical design study and experimental fabrication of long wavelength GaInNAs edge-emitting laser diode. The theoretical results reveals that optimal GaInNAs active region and device structure are acquired, where high material gain near 1.3 μm and precise optical mode confinement are obtained. Room temperature lasing emission around 1.27 μm with low threshold current and threshold current densities are achieved in broad area GaInNAs laser diode grown by molecular beam epitaxy. The theoretical results of photoluminescence spectrum and light-current-voltage characteristic shows a very good agreement with the experimental results.

Parametric optimization on optical properties of long-wavelength GaInNAs quantum well lasers

Optical properties of strained GaInNAs/GaAs quantum well (QW) is investigated using the many-body effects theory. The theoretical transition energies and GaNAs bowing parameter are fitted into photoluminescence (PL) spectrum from experiment. The theoretical results of PL spectrum and light-current-voltage characteristic shows a very good agreement with the experimental results.

Long-wavelength MBE grown GaInNAs quantum well laser emitting at 1270 nm

In this paper, we report on comprehensive theoretical optical properties analysis and experimental device electrical-optical characterization of long wavelength GaInNAs edge-emitting laser diode. The theoretical analysis demonstrates that a high quality GaInNAs active region and device design are devised, where high material gain near 1.3 μm and optimal optical mode confinement are calculated. Experimentally, room temperature lasing emission around 1.27 μm with threshold current densities of 670–810 A/cm2 is obtained from the fabricated broad area GaInNAs edge-emitting laser grown by molecular beam epitaxy technique.

GaInNAs QW with GaNAs intermediate layer for long wavelength laser

In this paper, we propose a structure, the GaInNAs QW with GaNAs intermediate layer (IML) which shows better performance in the optical properties as compared to the commonly used GaInNAs-GaAS rectangular quantum wells. The simulation software PICS3D is used in this work. Photoluminescence peak wavelength of 1327-nm GaInNAs-GaNAs IML laser has been achieved with a low threshold current 195mA and relatively high characteristic temperature, T0 of 270K. The IML structure is a promising invention for long wavelength GaAs-based laser in for the application in the fiber optic communication.