High power continuous operation of laser diodes at 1064 nm

Semiconductor Laser Diode Technology and Applications, 2012

Lithuanian Journal of Physics, 2005

Investigation of noise characteristics of InGaAsP / InP multiple-quantum-well laser diodes (LDs) near the threshold current region with the aim to reveal the LD quality and reliability problems is presented. A low quality and rapid degradation of particular laser diodes are reflected in noise characteristics: correlation factor between the optical and electrical fluctuations just after the threshold has a deep minimum and even drop to the negative values. The latter values are caused by leakage currents through the defects which determine the low quality and reliability of laser diodes. Optical noise intensity of a semiconductor laser below the threshold (here they operate as light emitting diodes) is low and the own noise level of a photodetector and measurement circuit is equal or exceeds it. In this case the laser diode optical noise has been measured using the correlation function method that increases optical noise measurement sensitivity by about three orders of magnitude.

Applied Optics, 1994

We present an electrical model for modulation and noise of laser diodes that takes spectral-hole burning into account and, unlike previous models, is accurate at the quantum level. The active part of the laser diode is represented by a capacitance-expressing carrier storage and a series resistance 1 + 3, where 3 is proportional to the spectral-hole depth. These two elements are followed by a negative impedance converter. The modulation rate measured on this electrical model is in excellent agreement with the theoretical expression. Amplitude noise is simulated by two independent noise sources whose spectral densities are independent of the nonlinearity. 34095,

Materials

GaAsBi is a suitable and very attractive material system to be used as an active layer in laser diodes (LDs). To understand the performance and the reliability of such devices and also for further laser diode improvements, the origin of noise sources should be clarified. A detailed study of near-infrared 1.09 μm wavelength GaAsBi type-I laser diodes using the low-frequency noise spectroscopy in a temperature range of (180–300) K is presented. Different types of voltage fluctuation spectral density dependencies on the forward current far below the lasing threshold have been observed. According to this, investigated samples have been classified into two groups and two equivalent noise circuits with the corresponding voltage noise sources are presented. Calculations on the voltage spectral density of the electrical noise and current-voltage characteristic approximations have been performed and the results are consistent with the experimental data. The analysis showed that one group of ...

Applied Optics, 1996

Intensity fluctuations (intensity noise) at 25 MHz of two semiconductor lasers are studied experimentally and theoretically. At this frequency two sources of intensity noise can be examined; quantum noise and noise originating from longitudinal mode competition. This latter source of noise occurs when more than one longitudinal mode competes for laser power. The intensity fluctuations for a free running laser diode (with no external optical feedback) and an external cavity laser (with external optical feedback) are measured as a function of injection current. An experimental value for the shot noise limit (the standard limit predicted by quantum mechanics) is also obtained, and all laser noise measurements are compared with this limit. We find that at twice the threshold injection current, the intensity noise of the free running laser is only 3.5 dB above the shot noise limit, and that of the external cavity laser 5 dB above the shot noise limit. iii STATEMENT OF PERMISSION TO U SE In presenting this thesis in partial fulfillment o f the requirements for a doctoral degree at Montana State University-Bozeman, I agree that the Library shall make it available to borrowers under rules o f the Library. I further agree that copying o f this thesis is allowable only for scholarly purposes, consistent with "fair use" as prescribed in the U S. Copyright Law. Requests for extensive copying or reproduction o f the thesis should be referred to University Microfilms International, 300 North Zeeb Road, Ann Arbor, Michigan 48106, to whom I have granted "the exclusive right to reproduce and distribute my dissertation in and from microfilm along with the non-exclusive right to

IEEE Journal of Quantum Electronics, 2000

We report terminal electrical noise measurements on 1.55-m DBR tunable laser diodes in the 1 Hz-1 MHz frequency range, performed using an electrical correlation method. These measurements are compared with a comprehensive electrical model based on rate equation formalism. Taking into account diffusion phenomenon and structural parameters, we obtain a complete agreement between the model and the measurements above threshold and a quite similar tendency below threshold. The influence of Bragg section bias is also discussed.

Microelectronics Reliability, 2015

Journal of the Optical Society of Korea, 2008

The relative intensity noise (RIN) characteristics in 405 nm blue laser diodes grown on wurtzite AlGaInN multiple quantum well structures were investigated using the rate equations with the quantum Langevin noise model. The device parameters were extracted from the optical gain properties of the MQW active region using the self-consistent numerical method developed for calculating the multiband Hamiltonian in the strained wurtzite crystal. These methods have been applied to laser diodes for various conditions including the external feedback and the high frequency current injection.

Journal of Lightwave Technology, 2002

An experimental study has been performed of the relative intensity noise (RIN) of a semiconductor laser in optical feedback regimes I to V. At low bias current, a low RIN is observed with low feedback ratio, the RIN increased in the coherence collapse regime (regime IV) and decreased in regime V. The RIN in regime V is lower than that of the solitary laser. For higher bias current, a higher feedback ratio is needed for the semiconductor laser to transit from regime IV to V. The measurements are found to be in good qualitative and quantitative agreement with theoretical predictions Index Terms-Laser diodes, noise, optical feedback.

IEEE Journal of Quantum Electronics, 1991

A general theory of linewidth for single-frequency semiconductor lasers is presented. The effects of spatially-distributed noise sources together with spatially-varying carrier and photon densities and injection current are analyzed in a rigorous manner by solution of the scalar wave equation. A new rate equation for the electric field is derived, in which the longitudinal effects are represented in the form of weight functions C N ( z ) and C s ( z ) . These functions express the sensitivity of the (output) field to local changes in carrier and photon density at the position 2. For Fabry-Perot lasers the z dependence of the C factors is shown to be negligible in agreement with the fact that spatial hole burning is not considered to be important for Fabry-Perot lasers. For DFB lasers however the z dependence is shown to be very significant. Examples of variation of the C factors with bias current are presented for a multielectrode DFB laser. A new formula for the spectral linewidth is derived and illustrated by numerical examples. The present theory can also account for time-varying distributions of carrier and photon densities due to noise or modulation. The change of distributions with bias current might have a strong influence on the linewidth and noise behavior.