Journal ArticleDOI
Achievement of 1 MHz frequency stability of semiconductor lasers by double-loop AFC scheme
TLDR
In this article, a temperature-controlling AFC system was developed to realize high-frequency stability with semiconductor lasers, and the frequency drift in DC operation can be reduced to below 1 MHz peak-to-peak.Abstract:
A temperature-controlling AFC system has been developed to realise high-frequency stability with semiconductor lasers. The frequency drift in DC operation can be reduced to below 1 MHz peak-to-peak. When necessary, the laser frequency can be modulated directly in the AFC state while the centre frequency is kept stabilised within 3 MHz. A heterodyne experiment was also performed using two frequency stabilised lasers; a stable IF output could be obtained for 10 min.read more
Citations
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Journal ArticleDOI
Simple formula giving spectrum-narrowing ratio of semiconductor-laser output obtained by optical feedback
Kazuro Kikuchi,T. Okoshi +1 more
TL;DR: In this paper, the spectrum-narrowing ratio of a GaAlAs laser with a small amount of optical feedback was measured as a function of the optical feedback power ratio.
Journal ArticleDOI
Heterodyne and Coherent Optical Fiber Communications: Recent Progress
TL;DR: The bit-error rate of a PCM-ASK/heterodyne optical communication system has been measured as a function of the received signal level, showing a good error performance close to the quantum-noise limitation.
Journal ArticleDOI
Recent progress in heterodyne/coherent optical-fiber communications
TL;DR: In this paper, a review of the recent achievements in bit error rate measurement of heterodyne/coherent optical-fiber systems are reviewed and compared with theory, and experimental systems described range from simple on-off-keying (PCM-PSK) heterodynes to sophisticated phase-shift keying (PSK)-based systems.
Journal ArticleDOI
Frequency stabilization of GaAlAs laser using a Doppler-free spectrum of the Cs-D 2 line
TL;DR: In this paper, the frequency stabilization of a GaAlAs laser using a Doppler-free spectrum in the saturated absorption of the Cs-D 2 line at 8521 nm was investigated.
Journal ArticleDOI
Estimation of linewidth enhancement factor of AlGaAs lasers by correlation measurement between FM and AM noises
Kazuro Kikuchi,T. Okoshi +1 more
TL;DR: In this article, the spectrum of the correlation between FM and AM noises is measured in a frequency range where the spontaneous emission noise is dominant, and then the α value is calculated from the measured correlation.
References
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Journal ArticleDOI
Novel method for high resolution measurement of laser output spectrum
TL;DR: In this paper, the authors proposed a method by which 50 kHz resolution can be obtained for measuring the spectrum of stabilised semiconductor laser with high spectral spread, and the principle, experimental set up and results are described.
Journal ArticleDOI
Computation of Bit-Error Rate of Various Heterodyne and Coherent-Type Optical Communication Schemes
TL;DR: The computation of the minimum signal level for achieving a prescribed bit-error rate in various heterodyne and coherent-type optical communication systems, as functions of the information-transmission rate and mixerdiode parameters is presented.
Journal ArticleDOI
Frequency stabilisation of semiconductor lasers for heterodyne-type optical communication systems
T. Okoshi,Kazuro Kikuchi +1 more
TL;DR: In this paper, an a.f.c. (automatic frequency control) experiment using a Peltier cooling element is described, where the frequency fluctuation can be reduced to below 10 MHz.
Journal ArticleDOI
High frequency stability of laser diode for heterodyne communication systems
F. Favre,D. Le Guen +1 more
TL;DR: In this article, the emission frequency of a single-mode GaAlAs laser diode was locked to a Fabry-Perot interferometer reference by using a high sensitivity and fast response feedback loop controlling the injection current.
Journal ArticleDOI
Heterodyne-type optical fiber communications
Takanori Okoshi,K. Kikuchi +1 more
TL;DR: Standard optical fiber communication systems employ intensity-modulation/direct-detection schemes, but some applications of optical Fiber communication exist in which a long repeater separation is the primary concern; an example is submarine optical cable communication between islands, in this case, the improvement of the bit-error rate (BER) by a coherent modulation/demodulation scheme such asPCM-PSK or PCM-FSK may be advantageous even at the sacrifice of simplicity and low cost.
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