- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
High-power single-longitudinal-mode double-tapered gain-coupled distributed feedback semiconductor lasers based on periodic anodes defined by i-line lithography
摘要： In this paper, we demonstrate a regrowth-free double-tapered gain-coupled distributed feedback semiconductor laser. It is designed based on periodic surface current injection to reach a high-power and single-longitudinal mode. A continuous-wave output power of over 1.2 W/facet is achieved at 4 A. High single-longitudinal-mode output power reaches up to 0.9 W/facet at 3 A at each uncoated facet. The side mode suppression ratio is nearly 30 dB at 980 nm. The 3 dB spectral width is less than 2.7 pm. The lateral far field divergence angle is only 14.5 °, the beam quality factor M2 is 1.7, achieving a near-diffraction-limit emission. Our device, produced by standard i-line lithography, enhances the output power while obtaining the pleasurable spectral and spatial properties. It has great potential in widespread commercial applications such as high efficiency pumping sources for its low-cost, easy fabrication technique and excellent performance.
关键词： Double-tapered,Distributed feedback lasers,Gain-coupled,Semiconductor lasers
更新于2025-11-28 14:24:03
-
990 nm High-power High-beam-quality DFB Laser With Narrow Linewidth Controlled By Gain-coupled Effect
摘要： High-power single-longitudinal-mode regrowth-free gain-coupled distributed feedback laser diode based on ridge waveguide with periodic current injection is achieved at 990 nm. Our device is fabricated only by standard i-line lithography with micron-scale precision, obtains an excellent performance at high injection current. A continuous-wave power of over 0.681 W is achieved at 3 A. The maximum continuous-wave power at single-longitudinal-mode operation is up to 0.303 W at 1.4 A. Narrow linewidth emission has been reached with a 3 dB spectrum width less than 1.41 pm. The high side mode suppression ratio is over 35 dB. The lateral far field divergence angle is only 15.05 °, the beam quality factor M 2 is 1.245, achieving a laterally near-diffraction-limit emission. It is more beneficial for single mode fiber coupling as pumping sources and other applications which require high beam quality at high power with easy fabrication technique.
关键词： narrow linewidth,Single-longitudinal mode,Gain-coupled DFB,Semiconductor lasers
更新于2025-11-28 14:24:03
-
Stable injection locking with slotted Fabry–Perot lasers at 2 <i>μ</i> m
摘要： Injection locking has many applications in telecommunications systems, such as narrowing linewidths, increasing bandwidth and improving filtering. Beyond telecommunications, injection locking is widely used in remote sensing. This is of particular interest for applications in the 2 μm region, where gases such as carbon dioxide, water vapour and methane have identifiable absorption features. In this paper, we demonstrate stable injection locking with slotted Fabry–Perot lasers in the 2 μm wavelength region. Injection locking was observed in both the optical domain and power spectrum; with key features recorded such as injection ‘pulling’, side-mode suppression and the characteristic quiet region in the electrical domain denoting single-frequency emission and stable locking. The effect of varying the injection ratio was investigated, with a decreased injection ratio corresponding to a reduction in the locking bandwidth. Finally, the lasers were shown to remain injection locked, with no thermal drift, for over 24 h, indicating their suitability for implementation in a real-world telecommunications system.
关键词： injection-locked lasers,semiconductor lasers,optical communications,optical sensing and sensors
更新于2025-11-28 14:23:57
-
Monodisperse Six-Armed Starbursts based on Truxene-Cored Multibranched Oligofluorenes: Design, Synthesis, and Stabilized Lasing Characteristics
摘要： A series of monodisperse six-armed conjugated starbursts (Tr1F, Tr2F and Tr3F) containing a truxene core and multibranched oligofluorene bridges capped with diphenylamine (DPA) units has been designed, synthesized, and investigated as robust gain media for organic semiconductor lasers (OSLs). The influence of electron-rich DPA end-groups on their optoelectronic characteristics has been discussed at length. DPA cappers effectively raise HOMO levels of the starbursts, thus enhancing the hole injection and transport ability. Solution-processed electroluminescence devices based on the resulting six-armed starbursts exhibited efficient deep-blue electroluminescence with clear reduced turn-on voltages (3.2~3.5 V). Moreover, the resulting six-armed molecules showed stabilized electroluminescence and amplified spontaneous emission with low thresholds (27.4~63.9 nJ pulse-1), high net gain coefficients (80.1~101.3 cm-1), and small optical loss (2.6~4.4 cm-1). Distributed feedback OSLs made from Tr3F exhibited low lasing threshold of 0.31 kW/cm2 (at 465 nm). The results suggest that the construction of truxene-centered six-armed conjugated starbursts with the incorporation of DPA units can effectively enhance EL properties by precisely regulating the HOMO energy levels, and further optimizing their optical gain properties.
关键词： Organic gain media,Organic light-emitting diodes (OLEDs),Conjugated starburst molecules,Organic semiconductor lasers (OSLs),HOMO levels
更新于2025-09-23 15:22:29
-
Picosecond-Range Avalanche Switching of Bulk Semiconductors Triggered by Steep High-Voltage Pulses
摘要： Experimental observation and numerical simulations of sub-nanosecond avalanche switching of Si and ZnSe bulk semiconductor structures initiated by high-voltage pulses with steep (dU/dt > 10 kV/ns) ramp are reported. The measured switching time is ～100 ps. The switching is sustainable and repetitive and has negligible jitter. Comparison of the experimental and numerical results suggests that after switching, the whole volume of the structure is uniformly ?lled with nonequilibrium electron–hole plasma.
关键词： semiconductor lasers,Power electronics,pulse-power system switches
更新于2025-09-23 15:21:21
-
High Speed Directly Modulated Fabry-Perot Lasers with an Ultra-Short Cavity Length
摘要： In this study, Fabry-Perot quantum well lasers with shortened cavity designs (25 and 50 μm) were fabricated. The devices had dry-etched and cleaved facets that exhibited an output power of up to 2.36 mW for a cavity length of 25 μm; good spectral performance was achieved. Single-optical-mode operation with better than 25dB of side mode suppression ratio can be achieved for the fabricated devices with 25- and 50-μm cavities. The short-cavity devices also exhibited high-speed modulation at elevated temperatures. Moreover, 25 Gb/s eye diagrams could be obtained at 65oC for the 25 μm device and 55oC for the 50 μm device. Due to their small area, ultra-short-cavity Fabry-Perot laser can be suitably used in next-generation light sources for optical communication.
关键词： Optical device fabrication,Semiconductor lasers,Laser cavity resonators,Amplitude modulation,Diode lasers,Quantum well lasers,Laser modes
更新于2025-09-23 15:21:01
-
Vertically coupled InP/InGaAsP microring lasers using a single epitaxial growth and single-side lithography
摘要： The experimental demonstration of vertical microring lasers requiring only one single epitaxial growth and two single-side lithographic steps is presented, in what is the simplest fabrication scheme for such devices published to date. The fabricated lasers show series resistance of around 20 Ω at forward bias, threshold currents at room temperature between 35 and 58 mA, and single-mode emission with a side-lobe suppression ratio higher than 30 dB. The measured optic output power level is of tens of microwatts. The approach allows the improvement of the optical features maintaining the simplicity of the manufacturing procedure.
关键词： semiconductor lasers,semiconductor waveguides,Integrated optics,ring lasers
更新于2025-09-23 15:21:01
-
Optimization of Transmitter-Side Signal Rotations in the Presence of Laser Phase Noise
摘要： In this paper, we present a 1050-nm electrically pumped microelectromechanically tunable vertical cavity surface-emitting laser (MEMS-VCSEL) with a record dynamic tuning bandwidth of 63.8 nm, suitable for swept-source optical coherence tomography (SS-OCT) imaging. These devices provide reduced cost and complexity relative to previously demonstrated optically pumped devices by obviating the need for a pump laser and associated hardware. We demonstrate ophthalmic SS-OCT imaging with the electrically-pumped MEMS-VCSEL at a 400 kHz axial scan rate for wide-field imaging of the in vivo human retina over a 12 mm × 12 mm field and for OCT angiography of the macula over 6 mm × 6 mm and 3 mm × 3 mm fields to show retinal vasculature and capillary structure near the fovea. These results demonstrate the feasibility of electrically pumped MEMS-VCSELs in ophthalmic instrumentation, the largest clinical application of OCT. In addition, we estimate that the 3 dB coherence length in air is 225 ± 51 m, far greater than required for ophthalmic SS-OCT and suggestive of other distance ranging applications.
关键词： Medical imaging,tunable lasers,optical coherence tomography,micro and nano opto-electromechanical systems (MOEMS),semiconductor lasers
更新于2025-09-23 15:21:01
-
Numerical model for small-signal modulation response in vertical-cavity surface-emitting lasers
摘要： We present a numerical model allowing for simulations of small-signal modulation (SSM) response of vertical-cavity surface-emitting lasers (VCSELs). The model of SSM response utilizes only the data provided by a static model of continuous-wave (CW) operation for a given bias voltage. Thus the fitting of dynamic measurement parameters is not needed nor used. The validity of this model has been verified by comparing experimental SSM characteristics of a VCSEL with the results of simulations. A good agreement between experiment and simulations has been observed. Based on the results obtained in the simulations of the existing laser, the impact of the number of quantum wells in the active region on the modulation properties has been calculated and analyzed.
关键词： optical data transfer,numerical modeling,semiconductor lasers,small-signal modulation response
更新于2025-09-23 15:21:01
-
Highly efficient surface-emitting semiconductor lasers exploiting quasi-crystalline distributed feedback photonic patterns
摘要： Quasi-crystal distributed feedback lasers do not require any form of mirror cavity to amplify and extract radiation. Once implemented on the top surface of a semiconductor laser, a quasi-crystal pattern can be used to tune both the radiation feedback and the extraction of highly radiative and high-quality-factor optical modes that do not have a defined symmetric or anti-symmetric nature. Therefore, this methodology offers the possibility to achieve efficient emission, combined with tailored spectra and controlled beam divergence. Here, we apply this concept to a one-dimensional quantum cascade wire laser. By lithographically patterning a series of air slits with different widths, following the Octonacci sequence, on the top metal layer of a double-metal quantum cascade laser operating at THz frequencies, we can vary the emission from single-frequency-mode to multimode over a 530-GHz bandwidth, achieving a maximum peak optical power of 240 mW (190 mW) in multimode (single-frequency-mode) lasers, with record slope efficiencies for multimode surface-emitting disordered THz lasers up to ≈570 mW/A at 78 K and ≈720 mW/A at 20 K and wall-plug efficiencies of η ≈ 1%.
关键词： quantum cascade laser,surface-emitting,Quasi-crystal,THz frequencies,Octonacci sequence,semiconductor lasers,distributed feedback
更新于2025-09-23 15:21:01