This reference book provides a fully integrated novel approach to the development of high power, single transverse mode, edge-emitting diode lasers by addressing the complementary topics of device ...engineering (Part 1), reliability engineering (Part 2) and device diagnostics (Part 3) in the same book in altogether nine comprehensive chapters, and thus closes the gap in the current book literature.Diode laser fundamentals are discussed, followed by an elaborate discussion of problem-oriented design guidelines and techniques, and by a systematic treatment of the origins of laser degradation and a thorough exploration of the engineering means to address for effective remedies and enhanced optical strength. The discussion covers also stability criteria of critical laser characteristics and key laser robustness factors. Clear design considerations are discussed in the context of reliability engineering concepts and models, along with typical programs for reliability tests and laser product qualifications. A final extended part of novel, advanced diagnostic methods covers in detail, for the first time in book literature, performance- and reliability-impacting factors such as temperature, stress and material instabilities.Further key features include:Furnishes comprehensive practical design guidelines by considering also reliability related effects and key laser robustness factors, and discusses basic laser fabrication and packaging issues. Discusses in detail diagnostic investigations of diode lasers, the fundamentals of the applied approaches and techniques, many of them pioneered by the author to be fit-for-purpose and novel in the application. Provides a systematic insight into laser degradation modes such as catastrophic optical damage, and covers a wide range of technologies to increase the optical strength of diode lasers. Discusses basic concepts and techniques of laser reliability engineering, and provides for the first time in a book details on a standard commercial program for testing the reliability of high power diode laser.Semiconductor Laser Engineering, Reliability and Diagnosticsreflects the extensive expertise of the author in the diode laser field both as a top scientific researcher as well as a key developer of high-power highly reliable devices. It features two hundred figures and tables illustrating numerous aspects of diode laser engineering, fabrication, packaging, reliability, performance, diagnostics and applications, and an extensive list of references to all addressed technical topics at the end of each chapter. With invaluable practical advice, this novel reference book is suited to practising researchers in diode laser technologies, and to postgraduate engineering students.
We report a widely tunable pulsed dysprosium (Dy) -doped fluoride fiber laser within a 545 nm continuous wavelength range around 3 μm, where a home-made random Raman fiber laser (RRFL) at 1.690 μm ...acts as the pump, and a commercial InAs saturable absorber (SA) is adopted as the Q-switcher. The designed RRFL, excited by a 1.055 μm ytterbium-doped fiber oscillator, can provide the 8 th order Stokes emission at 1.690 μm with a high spectral purity of 98.6% and a maximum output power of 14.4 W. Feeding it to a Dy cavity involving an InAs SA and a ruled diffraction grating in a Littrow configuration, stable Q-switching can be initiated and tuned within the continuous/total range of 2.775∼3.320 μm (545 nm)/2.765∼3.338 μm (573 nm), an extension of 50% over the prior 370 nm record Opt. Lett., vol. 44, no. 9, pp. 2322-2325, 2019, representing the widest level to date from a pulsed rare-earth-doped laser at any wavelengths, to the best of our knowledge. When the wavelength is tuned to 2.992 μm, a maximum average power of 106 mW with 460 ns pulse width, 125 kHz repetition rate, and 0.85 μJ pulse energy is achieved. This work marks the first pulsed Dy-doped fluoride fiber laser pumped at ∼1.7 μm while exhibiting the utility of InAs in pulse generation at the wavelengths of 3∼3.4 μm for the first time, to the best of our knowledge. The demonstration highlights the great potential of ∼1.7 μm pumped Dy-doped fluoride fiber laser as a platform for developing widely tunable pulsed sources in the 3 μm region of the mid-infrared.
In recent years, 2D layered materials, including graphene, topological insulators, transition metal dichalcogenides, black phosphorus, MXenes, graphitic carbon nitride, and metal‐organic frameworks, ...have attracted considerable interest due to their potential applications in the fields of physics, chemistry, biology, and energy. Their rise in the field of nonlinear photonics began around 2009 and has become an important research direction. Here, the synthesis techniques, nonlinear optical properties, integration strategies, and device applications of layered materials are reviewed. In terms of nonlinear optical properties, the focus is on saturable absorption and Kerr nonlinearity. On this basis, their applications in various pulsed lasers, including fiber lasers, solid‐state lasers, waveguide lasers, and related nonlinear optical phenomenon, are summarized. In addition, novel optical devices using layered materials, such as optical modulators, optical polarizers, optical switchers, and even all‐optical device, are also involved. It is believed that the development of 2D layered materials in the field of photonics will continue to deepen, thus laying a good foundation for its practical application.
Synthesis techniques, nonlinear optical properties, integration strategies, and device applications of 2D layered materials are reviewed. Especially, the current state of the art in the application, both in various mode‐locked/Q‐switched lasers and related nonlinear optical phenomenon and even novel optical devices, such as modulators, polarizers, isolators, all‐optical devices, and sensors, are summarized.
The Laser Wakefield Acceleration (LWFA) has advanced the accelerating gradient many orders of magnitude over the conventional technologies. Their application to high energy accelerators has been ...considered, while a new field of micrometric accelerators appears for medical applications.
After a brief examination of known insulating laser crystals and the stimulated emission channels of their generating activator ions, this article reviews recent advances in the development of novel ...lasing crystals and ceramics, as well as inorganic and organic nonlinear‐laser crystals for χ(3) and cascaded χ(3) ↔ χ(2) frequency converters. Several new modern attractive technologies in the physics and techniques of crystalline lasers are also discussed.
This reprint is the printed edition of the Special Issue published in Materials. The reprint provides an overview on current international research activities in the field of advanced pulse laser ...machining technology. It covers fundamental and applied aspects and collects contributions of renowned scientists from academics and industries working in the fields of laser processing, materials science, physics, chemistry, and engineering in order to foster the current knowledge and present new ideas for future applications and new technologies.
We demonstrate a high power two-dimensional vertical-cavity surface-emitting laser (VCSEL) array cooled by liquid metal. An output power of 1.1 kW at 808 nm with 39% power conversion efficiency (PCE) ...is obtained under continuous-wave (CW) operation. To the best of our knowledge, this is the highest output power reported for a laser diode array with liquid metal cooling. Moreover, the wavelength drift is only 1.2 nm from lasing threshold to 1.1 kW output power. Using this laser diode array as pumping module, a solid-state Nd:YAG slab laser at 1064 nm reaches 312 W output power. This verifies that the laser diode array cooled by liquid metal can be used as a pumping source for high power lasers. The higher power scaling can be achieved by two-dimensional geometric extension to the macro-channel heat sink and increasing the flux of the liquid metal.
Multi-wavelength distributed feedback laser array based tunable semiconductor lasers have been widely used owing to their high mode stability and simple tuning scheme. Comparing with the in-parallel ...laser array, the in-series one can avoid a large power loss caused by the optical combiner. However, the single-mode stability of an in-series laser array is vulnerable to the reflections of other lasers. Here we experimentally demonstrated a tunable in-series laser array with high single-mode stability and high uniformity of wavelength spacing. To reduce the impact of such reflections, the Bragg gratings in different lasers were designed in phase, and the grating phase error was reduced by utilizing the reconstruction-equivalent-chirp technique. Besides, a three-section laser structure was applied in each laser to increase the priority of the dominant lasing mode. Four lasers with small wavelength-spacings of 2.5 nm were integrated in the in-series laser array. According to the measurement results of 40 in-series laser arrays (160 lasers), wavelength deviations of 90.6% lasers were within ±0.2 nm, average wavelength spacings of 97.5% of the measured laser arrays were deviated from the design within ±0.2 nm, and SMSRs of 96.3% lasers were above 45 dB. The output power was above 25 mW and the relative intensity noise was below −130 dB/Hz. Like the in-parallel laser array, the proposed laser array can be applied in either continuous wavelength tuning or fast channel switching. For the continuous wavelength tuning applications, the 10-nm tuning range was obtained with a temperature tuning range of less than 20 °C. For the fast channel switching applications, four channels with 2.5-nm spacing are available, and the switching time between two channels was less than 300 ns.
PDF
