Applications Of Semiconductor Lasers Research Articles

Double-Junction Cascaded GaAs-Based Broad-Area Diode Lasers with 132W Continuous Wave Output Power

Improving the output power and efficiency of broad-area diode lasers is a prerequisite for the further development of fiber lasers, solid-state laser industries, and direct semiconductor laser applications. At present, the large amount of Joule heat generated by large drive currents and limited wall-plug efficiency presents the largest challenge for improving these lasers. In this paper, a multi-junction cascade laser with low Joule heat generation is demonstrated, showing large power and conversion efficiency. We fabricated devices with different junction numbers and compared their output power. We present double-junction lasers emitting at ~915 nm with an emitter width of 500 μm, delivering 132.5 W continuous wave output power at 70 A, which is the highest power reported so far for any single-emitter laser. The power conversion efficiencies are 66.7% and 60%, at 100 W and 132 W, respectively.

Time-delay signature suppression in delayed-feedback semiconductor lasers as a paradigm for feedback control in complex physiological networks.

Physiological networks, as observed in the human organism, involve multi-component systems with feedback loops that contribute to self-regulation. Physiological phenomena accompanied by time-delay effects may lead to oscillatory and even chaotic dynamics in their behaviors. Analogous dynamics are found in semiconductor lasers subjected to delayed optical feedback, where the dynamics typically include a time-delay signature. In many applications of semiconductor lasers, the suppression of the time-delay signature is essential, and hence several approaches have been adopted for that purpose. In this paper, experimental results are presented wherein photonic filters utilized in order to suppress time-delay signatures in semiconductor lasers subjected to delayed optical feedback effects. Two types of semiconductor lasers are used: discrete-mode semiconductor lasers and vertical-cavity surface-emitting lasers (VCSELs). It is shown that with the use of photonic filters, a complete suppression of the time-delay signature may be affected in discrete-mode semiconductor lasers, but a remnant of the signature persists in VCSELs. These results contribute to the broader understanding of time-delay effects in complex systems. The exploration of photonic filters as a means to suppress time-delay signatures opens avenues for potential applications in diverse fields, extending the interdisciplinary nature of this study.

Topological Optical Resonators and Their Application in Semiconductor Lasers

Topological Optical Resonators and Their Application in Semiconductor Lasers

Green-wavelength GaN-based photonic-crystal surface-emitting lasers

Visible-wavelength GaN-based photonic-crystal surface-emitting lasers (PCSELs) have attracted attention for various applications, such as materials processing, high-brightness illuminations, and displays. In this letter, we demonstrate GaN-based PCSELs at green wavelengths. We formed a photonic crystal (PC) in p-GaN and filled holes of the PC with SiO2 to ensure device stability. Through a current injection test under pulsed conditions and spectral analysis, we confirmed that the fabricated device possessed Γ-point single-mode oscillation at wavelengths above 505 nm. Our results have the potential to further expand the applications of PCSELs and semiconductor lasers in visible region.

Advances in silicon-based, integrated tunable semiconductor lasers

Abstract Tunable semiconductor lasers have many important applications such as wavelength division multiplexing, light detection and ranging, and gas detection. The increased interest in silicon photonics has led to the rapid development of miniaturized on-chip tunable semiconductor lasers. However, silicon has poor light-emitting properties. Therefore, realizing high-performance tunable semiconductor lasers requires the integration of light sources with silicon. In this study, we review silicon-based light source integration methods and the development of silicon-based integrated tunable semiconductor lasers. Considering that narrow-linewidth performance greatly expands the applications of tunable semiconductor lasers, methods for reducing the linewidth of tunable lasers are summarized. Finally, the development trends and prospects for silicon-based integrated light sources and silicon-based integrated tunable lasers are analyzed and discussed.

Elimination of catastrophic optical mirror damage in continuous-wave high-power laser diodes using multi-section waveguides.

One of the persistent obstacles for high-power laser diodes (LDs) has been the catastrophic optical mirror damage (COMD), which limits the operating power level and lifetime of commercial high-power LDs. The output facet of LD reaches a critical temperature resulting in COMD, which is an irreversible device failure. Here, we fabricate multi-section LDs by tailoring the waveguide structure along the cavity that separates the output facet from the heat-generating lasing region. In this method, the LD waveguide is divided into electrically isolated laser and window sections along the cavity. The laser section is pumped at a high current to achieve high output power, and the window is biased at a low current with negligible heat generation. This design restricts the thermal impact of the laser section on the facet, and the window section allows lossless transport of the laser to the output facet. The lasers were operated continuous-wave up to the maximum achievable power. While standard LDs show COMD failures, the multi-section waveguide LDs are COMD-free. Our technique and results provide a pathway for high-reliability LDs, which would find diverse applications in semiconductor lasers.

Editorial Introduction to the JSTQE Special Issue on Semiconductor Lasers

The papers in this special section focus on the topic of semiconductor lasers. Almost 60 years after their first demonstration this area of research remains one of the most active fields in photonics fueled both by the incorporation of new materials, structures and quantum effects as well as by the surge of novel applications that demand the unique properties of compactness, high-power, spectral richness and low linedwidth provided by these devices. These include communications, sensing, biophotonics and the more recent areas of lidar, optical beamforming, computing and quantum information systems. Each of them can leverage from the unique features of semiconductor lasers. The objective of this special section is to highlight recent progress, challenges and trends in innovative materials, geometries, modelling and applications of semiconductor lasers.

Manipulating Optical Scattering of Quasi-BIC in Dielectric Metasurface with Off-Center Hole.

Bound states in the continuum (BICs) correspond to a particular leaky mode with an infinitely large quality-factor (Q-factor) located within the continuum spectrum. To date, most of the research work reported focuses on the BIC-enhanced light matter interaction due to its extreme near-field confinement. Little attention has been paid to the scattering properties of the BIC mode. In this work, we numerically study the far-field radiation manipulation of BICs by exploring multipole interference. By simply breaking the symmetry of the silicon metasurface, an ideal BIC is converted to a quasi-BIC with a finite Q-factor, which is manifested by the Fano resonance in the transmission spectrum. We found that both the intensity and directionality of the far-field radiation pattern can not only be tuned by the asymmetric parameters but can also experience huge changes around the resonance. Even for the same structure, two quasi-BICs show a different radiation pattern evolution when the asymmetric structure parameter d increases. It can be found that far-field radiation from one BIC evolves from electric-quadrupole-dominant radiation to toroidal-dipole-dominant radiation, whereas the other one shows electric-dipole-like radiation due to the interference of the magnetic dipole and electric quadrupole with the increasing asymmetric parameters. The result may find applications in high-directionality nonlinear optical devices and semiconductor lasers by using a quasi-BIC-based metasurface.

The effect of parabolic potential on ground state energy and vibration frequency of magnetopolaron in asymmetric Gaussian potential quantum wells

Anisotropy parabolic potential (APP) effects on ground state (GS) energy [Formula: see text] and the vibration frequency (VF) [Formula: see text] of weak-coupled magnetopolaron (MP) in asymmetric Gaussian quantum wells (AGQWs) were investigated using the linear combination operator and unitary transformation method. The obtained results showed that [Formula: see text] and [Formula: see text] were increased by increasing the barrier height [Formula: see text] of AGQWs as well as transverse and longitudinal confined strengths [Formula: see text] and [Formula: see text] of APP and decreased with increase in the asymmetric Gaussian confinement potential (AGCP) range [Formula: see text] and transverse and longitudinal effective confined lengths [Formula: see text] and [Formula: see text] of APP. Thus, the GS energy and VF of MP could be changed by adjusting the confinement parameters of the APP and AGCP. The study of quantum wells’ semiconductor materials has broad potential applications in semiconductor lasers, optoelectronic devices and quantum information.

Review on the broadband time‐delay‐signature‐suppressed chaotic laser

AbstractChaotic laser generated by semiconductor lasers has been attached great importance in areas of secure communication, random number generation, and optical sensing. This article mainly reviews the research progress in the performance improvement of chaotic laser, including bandwidth enhancement and time‐delay signature suppression. First, the methods of chaotic laser generation and the existing problems are briefly introduced. Then, innovative methods for the optimization of chaotic characteristics are analyzed and discussed. The integrated chaotic semiconductor lasers are also discussed. At last, avenues for the development trends and future applications of chaotic semiconductor lasers are prospected.

The first principle calculation of improving p-type characteristics of BxAl1-xN

AlN is one of the third-generation semiconductor materials with wide application prospects due to its 6.2 eV band gap. In the application of semiconductor deep ultraviolet lasers, progress is slow due to the difficulty in obtaining p-type AlN with good performance. In this paper, the commonly used way of Mg directly as AlN dopant is abandoned, the inhibition effect of the B component on self-compensation of AlN crystal was studied. The improvement of self-compensation performance of AlN crystal by B component is studied by first principles calculation. The results show that the addition of B component can increase the hole concentration of AlN, which is conducive to the formation of p-type AlN.

Fiber coupling technology of high brightness blue laser diode

With the development and application of blue semiconductor lasers, it has become a research hotspot to obtain high brightness blue light source by beam combining technology. In order to obtain high brightness blue light output, 48 single tube semiconductor lasers with wavelength of 450 nm and output power of 3.5 W are focused and coupled into 105 μm/0.22 NA fiber by fast slow axis collimation and spatial beam combination. The blue light with power of 144.7 W and brightness of 11 MW/(cm2str) is obtained. The coupling efficiency is 93.78%, and the optical to optical conversion efficiency of the whole system is 86.13%.

Processing with Application of High-Power Semiconductor Laser – Theoretical Analysis of Heat Source and Application to Surface Processing –

Since the semiconductor laser has a high conversion efficiency, it has many expectations for effective application. There are increasing application trials of processing at actual factories and jobsites. Moreover, it can currently be used as a heat source to directly conduct processing. This is called direct-diode laser (DDL). However, since there is almost no information regarding the DDL structure and beam mode, there are no scientific documents for the theoretical treatment of this heat source. This is considered to have interfered with the broad application for development. This research establishes the theoretical analysis of the semiconductor heat source for material processing, and we attempted to employ a simulation for processing. To verify the established theory, surface hardening and welding processing were performed as typical processing.

Highly stable enhanced near-infrared amplified spontaneous emission in solution-processed perovskite films by employing polymer and gold nanorods.

Solution-processed organo-lead halide perovskites have emerged as promising optical gain media for tunable coherent light sources. The lasing performance is generally determined by the as-synthesized crystal quality. Noble metal nanostructures have been widely utilized to enhance optical responses due to their unique property of localized surface plasmon resonance. Herein, we report a simple method to enhance the near-infrared amplified spontaneous emission (ASE) performance of MAPbI3 polycrystalline films by solution-processing a PMMA spacer layer and an Au NR-doped PMMA top layer on perovskite thin films. As a result, the ASE threshold of the triple-layer perovskite film was significantly reduced by around 36% and the ASE intensity increased by 13.9-fold, compared to the pristine film. The underlying mechanism was attributed to the combined effects of surface passivation by PMMA and plasmon resonance enhancement of Au NRs. The passivation effect results in suppressing the nonradiative recombination and prolonging excited state decay, which have been investigated by transient absorption and pump-probe measurements. The plasmon effect is systematically studied through distance-dependent and spectra-dependent plasmon enhanced emission. The perovskite films with PMMA and Au NR coating showed great stability for 180 min under intense pulse laser continuous irradiation. The improved ASE performance still remained after leaving the film under the atmosphere for more than one month. We have successfully demonstrated a highly stable and sustained ASE output from MAPbI3 films under pulse laser excitation. This study provides a general approach for exploring plasmonic nanostructures in combination with polymers in the development and application of low-cost solution-processed semiconductor lasers.

Design and Synthesis of Conjugated Starburst Molecules for Optoelectronic Applications.

In recent years, conjugated starburst molecules, which possess a core unit with radial arms linked to the central axle, have become the research topic owing to their well-defined chemical structures, good solution processability, excellent reproducibility, and superior optoelectronic properties. The increasing interest in starburst systems is evidenced by progressively more frequent investigation on the use of these materials in optoelectronics. The ability to modify chemical structures through control over the core and arms on a molecular level can directly affect the electronic and electroluminescent characteristics of the resulting materials. In this review, we summarize and discuss main progress in our group concerning the rapidly developing field, in which strategies for the design and construction of starbursts are presented at length. Moreover, their application in organic light-emitting diodes (OLEDs) and organic semiconductor lasers (OSLs) are demonstrated as well, exploring the influence of molecular structures on the optoelectronic properties. Challenges and outlooks are also given at last.

A Highly Stable Source of Current Pulses with an Adjustable Amplitude of up to 350 A for a Nonlinear Complex Load

The application of high-power semiconductor lasers for creating a population inversion in active gaseous media is an integral part of studies that are aimed at the achievement of a sufficient level of laser-radiation energy to initiate a thermonuclear reaction. The stability of the laser radiation and, thus, the repeatability of experimental results, depend on the stability of the parameters of current pulses for pumping laser-diode arrays with a pulse amplitude of up to several hundred amperes. The flow of current pulses with such an amplitude through a cable that connects the load to the output of the current-pulse source must not lead to the formation of voltage pulses of opposite polarity across the load, which can damage it. This can be prevented by correcting the current pulse edges. It is proposed to develop a source of current pulses with a high amplitude on the basis of several modules of fast linear current amplifiers with individual control loops, whose outputs are connected in parallel. It is established that a compensation-type current sensor on the basis of the Hall effect is operable at high frequencies and can be used in these modules, but it has pronounced resonance properties, which must be canceled. It is shown that analog driving pulses of each module can be formed using aperiodic chains with parameters that eliminate oscillatory processes in the load circuit. A dynamic model of a module of the linear current amplifier and the calculation relationships for the parameters of its components, which follow from this model, are presented. The experimental results that confirm stability of the parameters of the formed current pulses are presented.

Progress Toward III–V Bismide Alloys for Near- and Midinfrared Laser Diodes

Bismuth-containing III–V alloys open-up a range of possibilities for practical applications in semiconductor lasers, photovoltaics, spintronics, photodiodes, and thermoelectrics. Of particular promise for the development of semiconductor lasers is the possibility to grow GaAsBi laser structures such that the spin–orbit splitting energy ( $\Delta _{{\text{SO}}}$ ) is greater than the bandgap ( $E_{g}$ ) in the active region for devices operating around the telecom wavelength of 1.55 μ m, thereby suppressing the dominant efficiency-limiting loss processes in such lasers, namely Auger recombination and intervalence band absorption. The $\Delta _{{\text{SO}}}\,> \,E_{g}$ band structure is present in GaAsBi alloys containing > 10% Bi, at which composition the alloy bandgap is close to 1.55 μ m on a GaAs substrate making them an attractive candidate material system for the development of highly efficient, uncooled GaAs-based lasers for telecommunications. Here, we discuss progress toward this goal and present a comprehensive set of data on the properties of GaAsBi lasers including optical gain and absorption characteristics and the dominant carrier recombination processes in such systems. Finally, we briefly review the potential of GaAsBiN and InGaAsBi material systems for near- and midinfrared photonic devices on GaAs and InP platforms, respectively.

Room-temperature 2D semiconductor activated vertical-cavity surface-emitting lasers

Two-dimensional (2D) semiconductors are opening a new platform for revitalizing widely spread optoelectronic applications. The realisation of room-temperature vertical 2D lasing from monolayer semiconductors is fundamentally interesting and highly desired for appealing on-chip laser applications such as optical interconnects and supercomputing. Here, we present room-temperature low-threshold lasing from 2D semiconductor activated vertical-cavity surface-emitting lasers (VCSELs) under continuous-wave pumping. 2D lasing is achieved from a 2D semiconductor. Structurally, dielectric oxides were used to construct the half-wavelength-thick cavity and distributed Bragg reflectors, in favour of single-mode operation and ultralow optical loss; in the cavity centre, the direct-bandgap monolayer WS2 was embedded as the gain medium, compatible with the planar VCSEL configuration and the monolithic integration technology. This work demonstrates 2D semiconductor activated VCSELs with desirable emission characteristics, which represents a major step towards practical optoelectronic applications of 2D semiconductor lasers.

Instabilities and Bifurcations of a DFB Laser Frequency-Stabilized by a High-Finesse Resonator

Recently reported miniature configurations with semiconductor distributed feedback lasers under resonant feedback are considered theoretically. Limiting instabilities and bifurcations are systematically explored by combining the theory of chirp reduction and a bifurcation analysis. It is shown that the regime of optimal chirp reduction also exhibits the best local stability. It suffers only from undamping of relaxation oscillations in a finite interval of feedback strength. The existence of a separate strong-feedback regime with high stability is consistent with the two experiments available so far. We regard this feature as a generic specificum of miniature configurations not known from large-scale setups. This regime can open new prospects for applications of compact frequency-stabilized semiconductor lasers with extremely low noise and small line width.

Comprehensive study of antireflection coatings for mid-infrared lasers

A comprehensive study is done for optimizing antireflection coatings at mid-infrared wavelengths around 3.4 μm for applications in semiconductor lasers. Different materials are tested for single and double layer coatings. The coatings are characterized by comparing the change in the threshold currents before and after coating the lasers. The change in the differential slope efficiency was used to estimate the loss in the coatings. The lowest value achieved for a single layer coating was 5% using aluminum oxide while a minimum value of reflectivity of 7 × 10−4 was achieved with a double layer coating of zinc selenide and silicon dioxide. The coatings' quality was tested using scanning electron microscopy and tape test. The study provides a comprehensive list of materials that can be used for antireflection coating applications in the mid-infrared region.