The Experts below are selected from a list of 125367 Experts worldwide ranked by ideXlab platform
Torgil Kjellberg - One of the best experts on this subject based on the ideXlab platform.
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complete single mode wavelength coverage over 40 nm with a super structure grating dbr laser
Journal of Lightwave Technology, 1995Co-Authors: M Oberg, P J Rigole, S Nilsson, T Klinga, L Backbom, K Streubel, J Wallin, Torgil KjellbergAbstract:The spectral characteristics of a widely tunable super structure grating distributed Bragg reflector (SSG-DBR) laser are investigated and the design considerations of the grating reflectors are given. By systematically adjusting the control currents of the two reflector Sections and the Phase Section it is experimentally shown that every wavelength in an interval of 40 nm can be reached with a side-mode suppression usually better than 30 dB. >
Kyung Hyun Park - One of the best experts on this subject based on the ideXlab platform.
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monolithic dual mode distributed feedback semiconductor laser for tunable continuous wave terahertz generation
Optics Express, 2009Co-Authors: Namje Kim, Jaeheon Shin, Eundeok Sim, Chul Wook Lee, Daesu Yee, Min Yong Jeon, Yudong Jang, Kyung Hyun ParkAbstract:We report on a monolithic dual-mode semiconductor laser operating in the 1550-nm range as a compact optical beat source for tunable continuous-wave (CW) terahertz (THz) generation. It consists of two distributed feedback (DFB) laser Sections and one Phase Section between them. Each wavelength of the two modes can be independently tuned by adjusting currents in micro-heaters which are fabricated on the top of the each DFB Section. The continuous tuning of the CW THz emission from Fe+-implanted InGaAs photomixers is successfully demonstrated using our dual-mode laser as the excitation source. The CW THz frequency is continuously tuned from 0.17 to 0.49 THz.
Lingjuan Zhao - One of the best experts on this subject based on the ideXlab platform.
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direct generation of broadband chaos by a monolithic integrated semiconductor laser chip
Optics Express, 2013Co-Authors: Lingjuan Zhao, Xi Tang, Zhuqiang Zhong, Guangqiong XiaAbstract:A solitary monolithic integrated semiconductor laser (MISL) chip with a size of 780 micrometer is designed and fabricated for broadband chaos generation. Such a MISL chip consists of a DFB Section, a Phase Section and an amplification Section. Test results indicate that under suitable operation conditions, this laser chip can be driven into broadband chaos. The generated chaos covers an RF frequency range, limited by our measurement device, of 26.5GHz, and possesses significant dimension and complexity. Moreover, the routes into and out of chaos are also characterized through extracting variety dynamical states of temporal waveforms, Phase portraits, RF spectra and statistical indicators.
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dual wavelength distributed bragg reflector semiconductor laser based on a composite resonant cavity
Chinese Physics B, 2012Co-Authors: Lingjuan Zhao, Cheng Chen, Wei WangAbstract:We report a monolithic integrated dual-wavelength laser diode based on a distributed Bragg reflector (DBR) composite resonant cavity. The device consists of three Sections, a DBR grating Section, a passive Phase Section, and an active gain Section. The gain Section facet is cleaved to work as a laser cavity mirror. The other laser mirror is the DBR grating, which also functions as a wavelength filter and can control the number of wavelengths involved in the laser action. The reflection bandwidth of the DBR grating is fabricated to have an appropriate value to make the device work at the dual-wavelength lasing state. We adopt the quantum well intermixing (QWI) technique to provide low-absorption loss grating and passive Phase Section in the fabrication process. By tuning the injection currents on the DBR and the gain Sections, the device can generate 0.596 nm-spaced dual-wavelength lasing at room temperature.
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frequency drift and instantaneous linewidth broadening of Phase Section tuned sg dbr laser
Optics Communications, 2011Co-Authors: Ninghua Zhu, Lingjuan Zhao, Liang Xie, Lixian Wang, Shuo Fu Chen, Jianguo Liu, Yun Zhang, Wei WangAbstract:Abstract We experimentally investigate the spectral dynamics of a Phase-Section tuned sampled-grating distributed Bragg reflector (SG-DBR) laser by using optical heterodyne method. The measured time-resolved spectra of the beat signal illustrate that the beat signal suffers from both frequency drift and instantaneous spectrum broadening, which indicates that the wavelengths of the lightwaves experience drift and jitter. We study the variation of frequency drift and instantaneous linewidth broadening with applied voltages. It is helpful in selection of optimum operating conditions and design of experimental setup. Experimental results demonstrate that the pulse-waveform can be used to reduce the frequency drift by shorting the beating time.
Yonglin Yu - One of the best experts on this subject based on the ideXlab platform.
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Novel Frequency Chirp Compensation Scheme for Directly Modulated SG DBR Tunable Lasers
IEEE Photonics Technology Letters, 2009Co-Authors: Robert Maher, Aleksandra Kaszubowska, Prince M. Anandarajah, Liam P Barry, Yonglin YuAbstract:The authors demonstrate a compensation scheme to reduce the frequency chirp associated with directly modulated sampled grating distributed Bragg reflector tunable lasers. Experimental results obtained show that the direct modulation of the laser's gain Section results in a large frequency chirp of 25 GHz. However, by simultaneous modulation of the laser's Phase Section this large frequency chirp can be significantly reduced.
Guymael De Naurois - One of the best experts on this subject based on the ideXlab platform.
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mid ir fiberoptic sensing and mode control in distributed feedback quantum cascade laser
Sensors, 2015Co-Authors: Guymael De NauroisAbstract:We present in water chemical spectroscopy by the use of a AgClBr fiber and a tunable mid-IR QCL. We will also show a new generation of multi-frequency DFB controlled by a monolithic Phase Section. Article not available.