Self-heating effect in 1.3 mu m p-doped InAs/GaAs quantum dot vertical cavity surface emitting lasers

The self-heating effect in 1.3 mu m p-doped InAs/GaAs quantum dot (QD) vertical cavity surface emitting lasers (VCSELs) has been investigated using a self-consistent theoretical model. Good agreement is obtained between theoretical analysis and experimental results under pulsed operation. The results show that in p-doped QD VCSELs, the output power is significantly influenced by self-heating. About 60% of output power is limited by self-heating in a device with oxide aperture of 5x6 mu m(2). This value reduces to 55% and 48%, respectively, as the oxide aperture increases to 7x8 and 15x15 mu m(2). The temperature increase in the active region and injection efficiency of the QDs are calculated and discussed based on the different oxide aperture areas and duty cycle.

COMPARISON BETWEEN THE INFLUENCES OF LAYER THICKNESSES AND ALAS MOLE FRACTION-X ON VERTICAL-CAVITY SURFACE-EMITTING LASERS

Based on the n(x, lambda), the calculation of the reflection spectrum for vertical cavity surface emitting lasers shows that the deviation of the central wavelength caused by the change of layer thickness is much more than that caused by the change of AlAs mole fractions. Therefore the control of the MBE growth rate is very important.

Effect of Mesa Size on Thermal Characteristics of Vertical-cavity Surface-emitting Lasers

The effect of mesa size on the thermal characteristics of etched mesa vertical-cavity surfaceemitting lasers(VCSELs) is studied. The numerical results show that the mesa size of the top mirror strongly influences the temperature distribution inside the etched mesa VCSEL. Under a certain driving voltage, with decreasing mesa size, the location of the maximal temperature moves towards the p-contact metal, the temperature in the core region of the active layer rises greatly, and the thermal characteristics of the etched mesa VCSELs will deteriorate.

Array for 980nm Vertical Cavity Surface Emitting Diodes and Detectors

Both the vertical cavity surface emitting diodes and detectors are fabricated by using the epitaxial wafer with resonant cavity structure. Their characteristics are analyzed. The light emitters have high spectral purity of 4.8nm and high electroluminescence intensity of 0.7mW while injection current is 50mA. A 1*16 array of surface emitting light device is tested on line by probes and then used for module. The light detectors have wavelength selectivity and space selectivity. The required difference in input mirror reflectivity between emitters and detectors can easily be achieved though varying the numbers of top DBR period by etching.

Small Signal Equivalent Circuit Model and Modulation Properties of Vertical Cavity-Surface Emitting Lasers

Small signal equivalent circuit model and modulation properties of vertical cavity-surface emitting lasers (VCSEL's) are presented. The modulation properties both in analytic-equation calculation and in circuit model simulation are studied. The analytic-equation calculation of the modulation properties is calculated by using Mathcad program and the circuit model simulation is simulation is simulated by using Pspice program respectively. The results of calculation and the simulation are in good agreement with each other. Experiment is performed to testify the circuit model.

Ultralow Threshold Red Vertical-Cavity Surface-Emitting Lasers

国家自然科学基金

Small signal equivalent circuit model of vertical cavity surface emitting lasers

Small signal equivalent circuit model of vertical cavity surface emitting lasers (VCSEL's) is given in this paper. The modulation properties of VCSEL are simulated using this model in Pspice program. The simulation results are good agree with experiment data. Experiment is performed to testify the circuit model.

HIGH-EFFICIENCY TOP SURFACE-EMITTING LASERS FABRICATED BY 4 IMPLANTATION USING TUNGSTEN WIRE AS MASK

We report the results of a high efficiency room temperature continuous wave (cw) vertical-cavity surface-emitting laser. The structure is obtained by four deep H+ implantation using tungsten wires as the mask. The fabrication process is the simplest ever reported in vertical-cavity surface-emitting laser fabrication. The largest differential quantum efficiency of 65% and maximum cw light output power over 4 mW have been achieved for the 15X15 mu m(2) device. (C) 1995 American Institute of Physics.

The enhancement of spontaneous emission factor in selectively oxidized vertical cavity lasers with double oxide layers

The behaviors of lateral propagating modes in the aperture and the oxidized regions are investigated numerically for selectively oxidized vertical-cavity surface-emitting lasers (VCSELs). The results show that the lateral propagating modes in the oxidized region are greatly affected by the oxide layer due to its low index, the modes are divergence for the VCSELs with sufficient thick double oxide layers. So the coupling between the modes in the aperture and oxidized regions is very weak, and we can expect that the lateral spontaneous emission is greatly affected in this case. Ignoring the contribution of the lateral spontaneous emission, we calculate spontaneous emission factor by counting the total number of the guided modes in selectively oxidized VCSELs with double oxide layers. The results agree very well with the reported measurements and are inversely proportional to the lateral index step.

The application of parallel optical transmitter and receiver modules in communication subsystems

A new 12 channels parallel optical transmitter module in which a Vertical Cavity Surface Emitting Laser (VCSEL) has been selected as the optical source is capable of transmitting 37.5Gbps date over hundreds meters. A new 12 channels parallel optical receiver module in which a GaAs PIN (p-intrinsic-n-type) array has been selected as the optical receiver unit is capable of responding to 30Gbps date. A transmission system based on a 12 channels parallel optical transmitter module and a 12 channels parallel optical receiver module can be used as a 10Gbps STM-64 or an OC-192 optical transponder. The parallel optical modules and the parallel optical transmission system have passed the test in laboratory.

VCSEL-based parallel optical transmission module

This paper describes the design process and performance of the optimized parallel optical transmission module. Based on 1x12 VCSEL (Vertical Cavity Surface Emitting Laser) array, we designed and fabricated the high speed parallel optical modules. Our parallel optical module contains a 1x12 VCSEL array, a 12 channel CMOS laser driver circuit, a high speed PCB (Printed Circuit Board), a MT fiber connector and a packaging housing. The L-I-V characteristics of the 850nm VCSEL was measured at the operating current 8mA, 3dB frequency bandwidth more than 3GHz and the optical output 1mW. The transmission rate of all 12 channels is 30Gbit/s, with a single channel 2.5Gbit/s. By adopting the integration of the 1x12 VCSEL array and the driver array, we make a high speed PCB (Printed Circuit Board) to provide the optoelectronic chip with the operating voltage and high speed signals current. The LVDS (Low-Voltage Differential Signals) was set as the input signal to achieve better high frequency performance. The active coupling was adopted with a MT connector (8 degrees slant fiber array). We used the Small Form Factor Pluggable (SFP) packaging. With the edge connector, the module could be inserted into the system dispense with bonding process.

High Speed VCSEL-Based Parallel Optical Transmission Modules

Design and fabrication of a parallel optical transmitter are reported. The optimized 12 channel parallel optical transmitter,with each channel＇s data rate up to 3Gbit/s,is designed, assembled, and measured. A top-emitting 850nm vertical cavity surface emitting laser（VCSEL） array is adopted as the light source,and the VCSEL chip is directly wire bonded to a 12 channel driver IC. The outputs of the VCSEL array are directly butt coupled into a 12 channel fiber array. Small form factor pluggable （SFP） packaging technology is used in the module to support hot pluggable in application. The performance results of the module are demonstrated. At an operating current of 8mA, an eye diagram at 3Gbit/s is achieved with an optical output of more than 1mW.

1.55-μm Si-based MOEMS optical tunable filter

A prototype 1.55-μm Si-based micro-opto-electro-mechanical-systems (MOEMS) tunable filter is fabricated, employing surface micromachining technology. Full-width-at-half-maximum (FWHM) of the transmission spectrum is 23 nm. The tuning range is 30 nm under 50-V applied voltage. The device can be readily integrated with resonant cavity enhanced (RCE) detector and vertical cavity surface emitting laser (VCSEL) to fabricate tunable active devices.

10Gbit/s甚短距离(VSR)并行光传输系统

介绍了一个适用于甚短距离(Very Short Reach,VSR)网络传输的并行光传输系统。系统的发射部分用垂直腔面发射激光器(vERTICAL cAVITY sURFACE eMITTING lASER,vcsel)1×12列阵代替传统的边发射激光器，接收部分也采用相应的探测器列阵，并由多模光纤列阵相连接，在300m距离内以单信道1．25Gbit/s速率实现的10Gbit/s的高传输速率。

16-channel 0.35 mu m CMOS/VCSEL optoelectronic devices

We report some investigations on vertical cavity surface emitting laser (VCSEL) arrays and VCSEL based optoelectronic smart photonic multiple chip modules (MCM), consisting of 1 x 16 vertical cavity surface emitting laser array and 16-channel lasers driver 0.35 mum CMOS circuit. The hybrid integrated multiple chip modules based on VCSEL operate at more than 2GHz in -3dB frequency bandwidth.