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High-power quantum well lasers with high brightness in the spectral range between 650 nm and 1080 nm will be presented. Improved layer structures with a narrow vertical far-field divergence down to angles of 15deg (full-width at h...
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High-power quantum well lasers with high brightness in the spectral range between 650 nm and 1080 nm will be presented. Improved layer structures with a narrow vertical far-field divergence down to angles of 15deg (full-width at half-maximum) were developed. For these layer structures, optimized tapered lasers were processed to achieve laterally a nearly diffraction-limited beam quality with beam propagation factors smaller than 2. Depending on the emission wavelength, the tapered devices reach an output power up to 12 W and a brightness of 1 GWmiddotcm-2middotsr-1.
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The nonlinear phenomena accompanying the process of light generation in high-power tapered semiconductor lasers are studied using a combination of simulation and experiment. Optical pumping, electrical overpumping, filamentation, ...
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The nonlinear phenomena accompanying the process of light generation in high-power tapered semiconductor lasers are studied using a combination of simulation and experiment. Optical pumping, electrical overpumping, filamentation, and spatial hole burning are shown to be the key nonlinear phenomena influencing the operation of tapered lasers at high output powers. In the particular tapered laser studied, the optical pumping effect is found to have the largest impact on the output beam quality. The simulation model used in this study employs the wide-angle finite-difference beam propagation method for the analysis of the optical propagation within the cavity. Quasi-three-dimensional (3-D) thermal and electrical models are used for the calculation of the 3-D distributions of the temperature, electrons, holes, and electrical potential. The simulation results reproduce key features and the experimental trends.
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摘要 :
The nonlinear phenomena accompanying the process of light generation in high-power tapered semiconductor lasers are studied using a combination of simulation and experiment. Optical pumping, electrical overpumping, filamentation, ...
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The nonlinear phenomena accompanying the process of light generation in high-power tapered semiconductor lasers are studied using a combination of simulation and experiment. Optical pumping, electrical overpumping, filamentation, and spatial hole burning are shown to be the key nonlinear phenomena influencing the operation of tapered lasers at high output powers. In the particular tapered laser studied, the optical pumping effect is found to have the largest impact on the output beam quality. The simulation model used in this study employs the wide-angle finite-difference beam propagation method for the analysis of the optical propagation within the cavity. Quasi-three-dimensional (3-D) thermal and electrical models are used for the calculation of the 3-D distributions of the temperature, electrons, holes, and electrical potential. The simulation results reproduce key features and the experimental trends.
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We present a simulation tool useful to optimize the design of semiconductor tapered lasers and to study the physical processes inside of them. This is achieved by using a state-of-the-art quasi-three-dimensional (quasi-3-D) electr...
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We present a simulation tool useful to optimize the design of semiconductor tapered lasers and to study the physical processes inside of them. This is achieved by using a state-of-the-art quasi-three-dimensional (quasi-3-D) electrical and thermal model, coupled to a two-dimensional (2-D) wide-angle beam propagation method optical model. A calibration procedure of model parameters is proposed to contribute to the development of reliable simulation tools. Different laser diodes with a tapered gain section, emitting at 735 and 975 nm, are used to validate the model through the extensive comparison of experimental and simulated results. The suitability of 2-D and 3-D electrical, thermal, and optical models is discussed in terms accuracy and computational effort.
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The beam properties of 980-nm tapered lasers with separate current drives for the ridge waveguide and tapered sections are analyzed by means of a comparison between simulations and experimental results. The simulations are perform...
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The beam properties of 980-nm tapered lasers with separate current drives for the ridge waveguide and tapered sections are analyzed by means of a comparison between simulations and experimental results. The simulations are performed with a new model for this type of tapered lasers, providing a good qualitative agreement with experiments. The observed improvement in the beam quality by a stronger pumping of the ridge waveguide section with respect to the tapered section is attributed to the reduction of the backward field intensity. The simulations show that this improvement, far from being a general rule, depends on the details of the device geometry.
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The performance of a multisection distributed Bragg reflector (DBR) semiconductor laser emitting around 1.06 μm is experimentally and theoretically investigated. A thermal-induced change of the refractive index implied by an incr...
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The performance of a multisection distributed Bragg reflector (DBR) semiconductor laser emitting around 1.06 μm is experimentally and theoretically investigated. A thermal-induced change of the refractive index implied by an increase in the injection current yields nearly periodic transitions between neighbouring cavity modes. These transitions are explained by means of a modal analysis and by numerical simulations based on the travelling wave model.
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Lasing emission at multiple wavelengths can be used in different sensing applications and in optical telecommunication. In this work, we report a six-wavelength distributed Bragg reflector (DBR) laser, emitting around 976 nm with ...
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Lasing emission at multiple wavelengths can be used in different sensing applications and in optical telecommunication. In this work, we report a six-wavelength distributed Bragg reflector (DBR) laser, emitting around 976 nm with six ridge waveguide (RW) structures, where individual DBR gratings are combined into a common front section. These six elements are individually addressable and biased one at a time for individual wavelength selection. The drawback of th is RW combination is observable in spatial characteristics where higher-order modes are supported. We addressed this issue by using a master oscillator power amplifier (MOPA) system that combines the six-wavelength MO laser with a tapered PA. Through this configuration, the PA acts as a spatial filter of the MO beam, providing a nearly diffraction-limited beam with M-1/e2(2) < 1.5. In addition, the described MOPA system 1 provides output powers around 4 W with spectral single-mode operation, with up to 9.36 nm of thermal wavelength tuning. We believe that the described MOPA configuration can be used in different applications, such as absorption spectroscopy. (C) 2021 Optical Society of America
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Tunable high-power diode lasers are key components in various established and emerging applications. In this work, we present a compact hybrid master oscillator power amplifier (MOPA) laser system. The system utilizes a tunable Ga...
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Tunable high-power diode lasers are key components in various established and emerging applications. In this work, we present a compact hybrid master oscillator power amplifier (MOPA) laser system. The system utilizes a tunable GaAs-based sampled-grating (SG) distributed Bragg reflector (DBR) laser as the master oscillator (MO), which emits around a wavelength of 970 nm in a single longitudinal mode with a spectral width below 20 pm. The SG-DBR laser consists of two SGs, each of which can be thermally tuned with microheaters. By tuning one of the two SGs, a discrete wavelength tuning of 21.1 nm can be obtained with a Vernier mode spacing of about 2.3 nm. By tuning both SGs, 23.5 nm of quasi-continuous tuning is obtained, with a mode spacing of about 115 pm. The coupling of the beam emitted by the MO into a tapered power amplifier provides an amplified output power in the watt range having a nearly diffraction-limited beam with a propagation factor of M-1/e2(2) = 1.6. The combination of high power and wide wavelength tuning in a compact system makes this light source ideal for, among other things, nonlinear frequency conversion. (C) 2018 Optical Society of America
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Two extraterrestrial particles from the asteroid Itokawa are investigated applying Shifted Excitation Raman Difference Spectroscopy (SERDS). These particles were returned by the Hayabusa mission of the Japanese Space Agency JAXA. ...
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Two extraterrestrial particles from the asteroid Itokawa are investigated applying Shifted Excitation Raman Difference Spectroscopy (SERDS). These particles were returned by the Hayabusa mission of the Japanese Space Agency JAXA. For SERDS a diode laser based microsystem light source at 488 nm is used for excitation. It has been found that fluorescence signals masking the Raman spectral features of interest can be substantially separated by applying SERDS. Therefore, SERDS improves the information obtained from the Raman spectra and enables a reliable analysis for investigations on extraterrestrial samples.
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Reliability tests for wavelength-stabilized compact diode laser systems emitting at 671 nm are presented. The devices were mounted on microoptical benches with the dimensions of 13 mm $times,$4 mm. Reflecting Bragg gratings were u...
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Reliability tests for wavelength-stabilized compact diode laser systems emitting at 671 nm are presented. The devices were mounted on microoptical benches with the dimensions of 13 mm $times,$4 mm. Reflecting Bragg gratings were used for wavelength stabilization and emission width narrowing. The reliability tests were performed at 25$^{circ}{rm C}$ and at an output power up to 10 mW per micrometer stripe width of the gain medium. Reliable operation could be demonstrated over a test time up to 14500 h at an output power up to 1.0 W. Environmental tests using random vibrations with acceleration up to 29 g were performed without deterioration of the devices.
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