Yuan Q, Liang Y, Jin L, Cheng L, Guan BO. Implementation of a widely tunable microwave signal generator based on dual-polarization fiber grating laser.
APPLIED OPTICS 2015;
54:895-900. [PMID:
25967802 DOI:
10.1364/ao.54.000895]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 01/02/2015] [Indexed: 06/04/2023]
Abstract
In this paper, we demonstrate the implementation of a widely tunable microwave signal generator based on a dual-polarization fiber grating laser. The laser contains two strong, wavelength-matched Bragg gratings photoinscribed in an Er-doped fiber and emits two polarization modes when pumped with a 980 nm laser diode. By beating the two modes, a microwave signal with a signal-to-noise ratio over 60 dB can be obtained. For a free running laser the fluctuations in intensity and frequency of the microwave signal are ±1 dB and ±5 kHz, respectively, and the noise level is about -40 dBc/Hz at 1 kHz. The frequency can be continuously tuned from 1.8 to 15.1 GHz, by transversely loading the laser cavity and changing the intracavity birefringence by use of a piezoelectric transducer-based mechanical device. The measured response time rate of tuning is about 90 MHz/μs and the intensity fluctuation at different frequencies is less than ±1.5 dB. The frequency fluctuation under loading is controlled within 1 MHz by introducing an electrical feedback.
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