Long Cavity Quantum Dot Laser Diode And Monolithic Passively Mode-locked Operation

Advantage of the single QD active layer is its potential for very low threshold current density, which in turn can produce low internal optical loss. The low threshold current density and low internal loss thus enable a significant increase in laser diode cavity length. Because of the importance of the threshold current density in heatsinking, future technology of broad-area monolithic laser diodes can be implemented. The dissertation describes the development and the unique characteristics of single QD active layer laser with long cavity. The data are presented on single layer QD laser diodes that reach threshold current densities values of 11.7 A/cm2 in a p-up mounted 2 cm long cavity and as low as 10 A/cm2, with CW output power of 2 W in a p-down mounted 1.6 cm long cavity. The 8.8 A/cm2 in a p-down mounted 2 cm long cavity is reported. To our knowledge the value 8.8 A/cm2 is the lowest threshold current density ever reported for a room temperature laser diode. These single layer QD laser diodes reach an internal loss of ~0.25 cm-1, which is also the lowest ever reported for a room temperature laser diode. These unique characteristics of single layer QD and laser diode size are potentially promising for the monolithic mode-locked laser because of relatively high peak power with a low repetition rate that is on the order of a few GHz, which can be the novel device for external clocking in the optical interconnect applications. In this dissertation, the stable optical pulse train in a 40 µm wide stripe with a repetition rate of 3.75 GHz with 1.1 cm cavity length through the passive mode-locked onto the monolithic two-section device fabricated from this single layer QD laser is observed

Large Cavity Single Layer Quantum Dot Laser Diodes

Large cavity, very low threshold single layer quantum dot laser diodes with threshold current density of 10 A/cm2, output power \u3e 2 W, and very-low internal loss of 0.25 cm-1 are achieved at CW room-temperature. Mode-locked operation of a large cavity laser diode with 40 μm stripe width is demonstrated at 3.75 GHz repetition rate. ©2008 IEEE

High power high brightness volume Bragg semiconductor lasers

While semiconductor lasers are the most efficient high power sources of optical radiation, their wide and unstable emission spectra and high divergence of radiation impede their utilization in a number of important industrial, medical, military, and scientific applications. One of the widely studied approaches to improve brightness of semiconductor lasers is the use of external resonators that provide spectral or angular mode selection. The most successful approach that was demonstrated during last ten years is the use of volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass for spectral and angular selection in semiconductor laser resonators along with coherent and spectral beam combining. This paper describes increasing brightness of different types of single emitters and multichannel laser systems enabled by achievements in development of low absorption PTR glass and high optical quality of VBGs. © 2012 IEEE

High Power High Brightness Volume Bragg Semiconductor Lasers

While semiconductor lasers are the most efficient high power sources of optical radiation, their wide and unstable emission spectra and high divergence of radiation impede their utilization in a number of important industrial, medical, military, and scientific applications. One of the widely studied approaches to improve brightness of semiconductor lasers is the use of external resonators that provide spectral or angular mode selection. The most successful approach that was demonstrated during last ten years is the use of volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass for spectral and angular selection in semiconductor laser resonators along with coherent and spectral beam combining. This paper describes increasing brightness of different types of single emitters and multichannel laser systems enabled by achievements in development of low absorption PTR glass and high optical quality of VBGs. © 2012 IEEE

Single Wavelength Square Semiconductor Laser With Quad Grating-Coupled Surface-Emitting Outputs

We present a square broad area semiconductor surface emitting laser lasing in orthogonal directions with feedback provided by four dual grating reflectors. The outputs of the device, having two orthogonal polarizations, overlap above the laser. © 2006 Optical Society of America

Threshold And Temperature Dependence Of Quantum Dot Laser Diodes Approaching Ideal Performance

Low threshold QD laser with threshold current density \u3c10 A/cm 2 is experimentally shown and threshold current temperature dependence of a QD laser with an ideal delta function density of electronic states is analyzed. ©2009 Optical Society of America

Threshold And Temperature Dependence Of Quantum Dot Laser Diodes Approaching Ideal Performance

Low threshold QD laser with threshold current density \u3c10 A/cm2 is experimentally shown and threshold current temperature dependence of a QD laser with an ideal delta function density of electronic states is analyzed. © 2009 Optical Society of America

Micro And Nano-Optics In Surface Emitting Lasers

This paper investigates surface emitting lasers using nano and micro-optics integration for spatial and spectral beam control. Specific results will be presented for beam shaping, anti-reflection coatings, and integrated wavelength locking schemes for high power devices. © 2006 Optical Society of America