Pulsed Lightwave Frequency Synthesizer System Using an EDFA and AOD in a Fiber Loop
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概要
- 論文の詳細を見る
We report here a pulsed lightwave frequency synthesizer system that is composed of a pulsed lightwave sweep frequency generator and a tracking generator. The key advance in the sweep generator is the use of a dynamically gain controlled EDFA. The combination of feedback and feedforward dynamic gain control effectively compensates EDFA gain fluctuation and equalizes fiber loop loss so that the initial pulse waveform and amplitude is retained in the loop at large circuit numbers. Over 1000 pulsed lightwave frequencies are synthesized in 250 MHz steps by the sweep generator. Almost flat response (±0.55 dB variation) is realized up to 240GHz. The power spectrum decreases by 67% (1.7 dB down) at 250 GHz. The peak level of the pulses output from the loop is about -4 dBm. Tracking generator and total synthesizer system performance are evaluated by (a) beat frequency between the tracking generator and the master lightwave source, (b) beat frequency between two tracking generators, and (c) a frequency chain between the master lightwave source and another HCN stabilized lightwave source via the synthesizer system. A continuous lightwave frequency locked to a frequency selected from the pulsed sweep frequency signal is demonstrated at over 200 GHz to have an instability of ±5 MHz. Absolute accuracy of the lightwave frequency emitted from the synthesizer system is about ±10 MHz. Therefore, the relative accuracy of the lightwave frequency is as high as ±5×10^lt-8gt.
- 社団法人電子情報通信学会の論文
- 1995-05-25
著者
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Aida Kazuo
Ntt Optical Network Systems Laboratories
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Nakagawa Kiyoshi
NTT Optical Network Systems Laboratories