- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
High-power, high-spectral-purity GaSb-based laterally coupled distributed feedback lasers with metal gratings emitting at 2? <i> <b>μ</b> </i> m
摘要： We report on the fabrication of high-power, high-spectral-purity GaSb-based laterally coupled distributed feedback (LC-DFB) lasers emitting at 2 μm. Second-order Chromium-Bragg-gratings are fabricated alongside the ridge waveguide by lift off. Due to the introduction of gain coupling, the lasers exhibit a stable single mode operation [side-mode suppression ratio (SMSR) >40 dB] from 10 °C to 50 °C and the maximum SMSR is as high as 53 dB. At a heat-sink temperature of 10 °C, the lasers emit more than 40 mW continuous-wave in a single longitudinal mode. A high external quantum efficiency of 48% is obtained, resulting in a notable increase in power conversion efficiency peaking at 13%. The lasers achieve a comparable output power with that of the index-coupled LC-DFB lasers, while maintaining a better single mode performance. Thus, we prove the feasibility of the metal-grating LC-DFB structure to achieve high-power, frequency-stable semiconductor lasers through a simpler and much more convenient way.
关键词： metal gratings,high-spectral-purity,high-power,distributed feedback lasers,GaSb-based lasers
更新于2025-11-28 14:24:03
-
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
-
Sub-400 nm film thickness determination from transmission spectra in organic distributed feedback lasers fabrication
摘要： The design and fabrication of thin-film based organic optoelectronic devices require knowledge of the film optical properties. A low-cost and non-destructive method often used for optical characterization of films is the well-established spectrophotometric envelope method. However, this method is typically limited to thickness above 400 nm, a value often higher than that of the films involved in these devices. This paper studies a procedure to obtain the thickness of sub-400 nm active films from their spectrophotometric trace when the refractive index is previously known. The proposed procedure is based on comparing the experimental transmission spectrum in the transparent spectral window with that obtained by simulation. The capabilities of the proposed method are demonstrated here by its application in the fabrication of organic distributed-feedback lasers where a fine control of film thickness is important to obtain an optimized and reproducible response. Results were verified with other techniques, such as ellipsometry and profilometry. Thus, with the proposed method, film thickness can be easily determined down to 40 nm maintaining an accuracy of about 5 nm even for films with low refractive index (1.5-1.7). Different methods to determine refractive index of these films are also discussed.
关键词： Optical characterization,Thin film thickness,Transmission spectra,Distributed feedback lasers
更新于2025-09-19 17:13:59
-
[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Applications of Single Frequency Blue Lasers
摘要： Gallium nitride (GaN) sources are becoming a regular part of today’s world and are now key devices for lighting infrastructures, communications systems and quantum applications, amongst others. In particular, many applications have seen the shift from LEDs to laser diodes to make use of higher powers, higher bandwidths and increased transmission distances. Laser communication systems are well established, however there are applications where the ability to select a single emitted wavelength is highly desirable, such as quantum atomic clocks or in filtered communication systems. Distributed feedback (DFB) lasers have been realised emitting at a single wavelength where the grating structure is etched into the sidewall of the ridge. The main motivation in developing these lasers is for the cooling of ions in atomic clocks; however their feasibility for optical communications is also explored. Narrow linewidth lasers are desirable and this paper will explore how this is achieved. Data rates in excess of 1 Gbit/s have also been achieved in a directly modulated, unfiltered system. These devices lend themselves towards wavelength division multiplexing and filtered optical communications systems and this will be analysed further in the work presented here.
关键词： gallium nitride,optical atomic clocks,optical communications,distributed feedback lasers
更新于2025-09-19 17:13:59
-
[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Study on DFB semiconductor laser based on sampled moiré grating integrated with grating reflector
摘要： We proposed a new kind of distributed feedback (DFB) semiconductor laser based on the sampled moiré grating (SMG) integrated with a grating reflector (GR). Coupling coefficient along laser cavity can be easily controlled and π phase shift (π-PS) can be introduced by SMG. The GR, which is a uniform sampled grating, only provides reflection for facet light. The both facets are coated with anti-reflection coatings (AR/AR) to avoid the influence of facet-phase. Therefore, more output power, single longitudinal mode (SLM) operation and high wavelength precision can be simultaneously achieved. An 8-channel DFB laser array based on the proposed structure has also been simulated.
关键词： distributed feedback lasers,sampled moiré grating,grating reflector,laser array
更新于2025-09-16 10:30:52
-
[IEEE 2019 Compound Semiconductor Week (CSW) - Nara, Japan (2019.5.19-2019.5.23)] 2019 Compound Semiconductor Week (CSW) - Thermal dependence of the emission linewidth of $1.52-\mu \mathrm{m}$ single mode InAs/InP quantum dot lasers
摘要： This paper experimentally investigates the thermal dependence of the emission linewidth of 1.52-μm single mode InAs/InP quantum dot lasers. Using a distributed feedback cavity made with symmetric antireflection coatings, a minimum linewidth of 300 kHz is unveiled. This narrow line is found rather constant with the injection current and the temperature range (293 K - 313 K). However, under certain operating conditions, a linewidth rebroadening is also observed, which may be attributed to the spectral hole burning and to the variations of the alpha-factor with the temperature and bias current. Nevertheless, these results confirm the potential of this technology for manufacturing low-phase noise oscillators for coherent optical communications.
关键词： Quantum dots,Distributed feedback lasers,spectral linewidth,rebroadening
更新于2025-09-12 10:27:22
-
Electronically Tunable Distributed Feedback (DFB) Laser on Silicon
摘要： An electronically tunable distributed feedback (DFB) laser heterogeneously integrated on a silicon photonics platform is experimentally demonstrated. Tuning is achieved through carrier injection into the tuning layer of a tunable twin-guide III–V membrane on silicon. A 2 nm continuous tuning range is achieved with a single tuning current. Continuous-wave single-mode laser operation with a side-mode suppression ratio larger than 44 dB across the tuning range is obtained. Measured wavelength switching times are on the order of 3 ns and non-return-to-zero on-o? keying direct modulation at 12.5 Gbit s?1 is readily achieved. This work can be a major advance toward the realization of optical burst or packet switching systems for future data center networks.
关键词： silicon photonics,electronic wavelength tuning,distributed feedback lasers,semiconductor lasers
更新于2025-09-11 14:15:04
-
[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Time-modulated Periodic Systems with PT Symmetry
摘要： This work explores the effects of parity-time (PT) symmetry in time-modulated periodic systems. Mechanisms for dynamic tunability of exceptional points are presented. We show that synthetic linear momentum imparted by time-modulation leads to uni-directional exceptional points. Such structures could see application in uni-directional lasers with tunable directionality.
关键词： semiconductor lasers,photonic crystals,distributed feedback lasers,time-varying circuits,parity-time symmetry,time-varying systems,optical modulation
更新于2025-09-04 15:30:14