The Experts below are selected from a list of 10329 Experts worldwide ranked by ideXlab platform
Benjamin S Williams - One of the best experts on this subject based on the ideXlab platform.
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phase locking of a 2 7 thz quantum cascade laser to a microwave reference
Optics Letters, 2009Co-Authors: P Khosropanah, Andrey M. Baryshev, J N Hovenier, Wen Zhang, Willem Jellema, J R Gao, T M Klapwijk, D G Paveliev, Benjamin S WilliamsAbstract:We demonstrate the phase locking of a 2.7 THz metal–metal waveguide quantum cascade laser (QCL) to an external microwave Signal. The reference is the 15th harmonic, generated by a semiconductor superlattice nonlinear device, of a Signal at 182 GHz, which itself is generated by a multiplier chain (x12) from a microwave synthesizer at ~15 GHz. Both laser and reference radiations are coupled into a bolometer mixer, resulting in a Beat Signal, which is fed into a phase-lock loop. The spectral analysis of the Beat Signal confirms that the QCL is phase locked. This result opens the possibility to extend heterodyne interferometers into the far-infrared range.
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phase locking and spectral linewidth of a two mode terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Andrey M. Baryshev, J N Hovenier, A J L Adam, Irmantas Kašalynas, T O Klaassen, Benjamin S WilliamsAbstract:We have studied the phase locking and spectral linewidth of an ? 2.7?THz quantum cascade laser by mixing its two lateral lasing modes. The Beat Signal at about 8?GHz is compared with a microwave reference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow Beat linewidth of less than 10?Hz. Under frequency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ? 6.3?kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.
J N Hovenier - One of the best experts on this subject based on the ideXlab platform.
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phase locking of a 2 7 thz quantum cascade laser to a microwave reference
Optics Letters, 2009Co-Authors: P Khosropanah, Andrey M. Baryshev, J N Hovenier, Wen Zhang, Willem Jellema, J R Gao, T M Klapwijk, D G Paveliev, Benjamin S WilliamsAbstract:We demonstrate the phase locking of a 2.7 THz metal–metal waveguide quantum cascade laser (QCL) to an external microwave Signal. The reference is the 15th harmonic, generated by a semiconductor superlattice nonlinear device, of a Signal at 182 GHz, which itself is generated by a multiplier chain (x12) from a microwave synthesizer at ~15 GHz. Both laser and reference radiations are coupled into a bolometer mixer, resulting in a Beat Signal, which is fed into a phase-lock loop. The spectral analysis of the Beat Signal confirms that the QCL is phase locked. This result opens the possibility to extend heterodyne interferometers into the far-infrared range.
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phase locking and spectral linewidth of a two mode terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Andrey M. Baryshev, J N Hovenier, A J L Adam, Irmantas Kašalynas, T O Klaassen, Benjamin S WilliamsAbstract:We have studied the phase locking and spectral linewidth of an ? 2.7?THz quantum cascade laser by mixing its two lateral lasing modes. The Beat Signal at about 8?GHz is compared with a microwave reference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow Beat linewidth of less than 10?Hz. Under frequency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ? 6.3?kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.
Andrey M. Baryshev - One of the best experts on this subject based on the ideXlab platform.
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phase locking of a 2 7 thz quantum cascade laser to a microwave reference
Optics Letters, 2009Co-Authors: P Khosropanah, Andrey M. Baryshev, J N Hovenier, Wen Zhang, Willem Jellema, J R Gao, T M Klapwijk, D G Paveliev, Benjamin S WilliamsAbstract:We demonstrate the phase locking of a 2.7 THz metal–metal waveguide quantum cascade laser (QCL) to an external microwave Signal. The reference is the 15th harmonic, generated by a semiconductor superlattice nonlinear device, of a Signal at 182 GHz, which itself is generated by a multiplier chain (x12) from a microwave synthesizer at ~15 GHz. Both laser and reference radiations are coupled into a bolometer mixer, resulting in a Beat Signal, which is fed into a phase-lock loop. The spectral analysis of the Beat Signal confirms that the QCL is phase locked. This result opens the possibility to extend heterodyne interferometers into the far-infrared range.
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phase locking and spectral linewidth of a two mode terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Andrey M. Baryshev, J N Hovenier, A J L Adam, Irmantas Kašalynas, T O Klaassen, Benjamin S WilliamsAbstract:We have studied the phase locking and spectral linewidth of an ? 2.7?THz quantum cascade laser by mixing its two lateral lasing modes. The Beat Signal at about 8?GHz is compared with a microwave reference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow Beat linewidth of less than 10?Hz. Under frequency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ? 6.3?kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.
S.v. Chernikov - One of the best experts on this subject based on the ideXlab platform.
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direct continuous wave measurement of n2 in various types of telecommunication fiber at 1 55 μm
Optics Letters, 1996Co-Authors: A Boskovic, S.v. Chernikov, J.r. Taylor, L Grunernielsen, O A LevringAbstract:A method for measuring the nonlinear refractive index of optical fibers with an error of less than 5% is demonstrated. The technique is based on measuring the nonlinear phase shift experienced by a dual-frequency Beat Signal, permitting a simple, highly sensitive, accurate, repeatable, and easily automated measurement procedure and sampling. Measurements of the nonlinear coefficient in standard telecommunication, dispersion-shifted, and a number of dispersion-compensated fibers are presented.
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Measurement of normalization factor of n(2) for random polarization in optical fibers.
Optics letters, 1996Co-Authors: S.v. Chernikov, J.r. TaylorAbstract:The 8/9 normalization coefficient for the nonlinear refractive index in nonpolarization-maintaining optical fibers is confirmed directly by measurement of the ratio of the self- and cross-phase modulation coefficients for two orthogonal polarizations. The nonlinear phase shift is accurately measured with a dual-frequency Beat Signal as a pump source.
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comblike dispersion profiled fiber for soliton pulse train generation
Optics Letters, 1994Co-Authors: S.v. Chernikov, J.r. Taylor, Raman KashyapAbstract:A novel optical fiber [comblike dispersion-profiled fiber (CDPF)] that consists of a chain of alternating segments of standard telecommunication fiber and dispersion-shifted fiber is proposed for the generation of a soliton pulse train based on nonlinear transformation of an optical Beat Signal. A totally integrated all-optical fiber source of a 59.1-GHz train of 2.2-ps solitons is demonstrated with a CDPF. For a Beat Signal generator we use a dual-frequency erbium fiber laser incorporating fiber grating reflectors that provides 16-kHz linewidths and a low phase noise of optical Beating (<5 × 10−5). Significant suppression of stimulated Brillouin scattering, which is essential for this technique, is achieved in the CDPF.
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integrated all optical fibre source of multigigahertz soliton pulse train
Electronics Letters, 1993Co-Authors: S.v. Chernikov, J.r. Taylor, Raman KashyapAbstract:A 59.1 GHz train of 2.2 ps solitons with low phase noise (<5×10−5) is generated by a novel, passive, all optical fibre source. The technique is based on transformation of a dual frequency Beat Signal generated by a 16 kHz line width erbium fibre DBR laser having a selectable and highly stable frequency separation, into a soliton train in a comblike dispersion profiled fibre, a novel fibre design which uses conventional optical fibres.
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114 gbit s soliton train generation through raman self scattering of a dual frequency Beat Signal in dispersion decreasing optical fiber
Applied Physics Letters, 1993Co-Authors: S.v. Chernikov, E M Dianov, D J Richardson, R I Laming, D N PayneAbstract:We report the generation of 114 Gbit/s trains of 250 fs fundamental solitons. The pulses are generated due to the conversion of an intense optical Beat Signal (generated from two DFB laser diodes and an erbium doped fiber amplifier combination) into a soliton train due to nonlinear propagation in a 1.6 km fiber of steadily decreasing dispersion. The train repetition rate corresponds to the Beat frequency of the input Signal and was readily tunable between 80 and 120 GHz. The results of a computer simulation of the system are found to be in good qualitative agreement with the experimental observations.
A J L Adam - One of the best experts on this subject based on the ideXlab platform.
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phase locking and spectral linewidth of a two mode terahertz quantum cascade laser
Applied Physics Letters, 2006Co-Authors: Andrey M. Baryshev, J N Hovenier, A J L Adam, Irmantas Kašalynas, T O Klaassen, Benjamin S WilliamsAbstract:We have studied the phase locking and spectral linewidth of an ? 2.7?THz quantum cascade laser by mixing its two lateral lasing modes. The Beat Signal at about 8?GHz is compared with a microwave reference by applying conventional phase lock loop circuitry with feedback to the laser bias current. Phase locking has been demonstrated, resulting in a narrow Beat linewidth of less than 10?Hz. Under frequency stabilization we find that the terahertz line profile is essentially Lorentzian with a minimum linewidth of ? 6.3?kHz. Power dependent measurements suggest that this linewidth does not approach the Schawlow-Townes limit.