Single-frequency synthesis at telecommunication wavelengths.
We report an optical single-frequency synthesizer at the 1.55 microm telecommunications band. Output from a continuous-wave external cavity diode laser is frequency doubled and phase locked to a predetermined component of a Ti:S laser frequency comb. The synthesizer is capable of generating a single user-specified frequency from an atomic time base within the 192-196 THz gain bandwidth of an erbium-doped fiber amplifier. By tuning the repetition rate of the femtosecond laser the synthesized optical frequency can be swept with sub-kilohertz step size. Frequency sweeps of several GHz are realized by automatically re-locking the diode laser to adjacent comb components during frequency sweep. We demonstrate the operation of the device by presenting results of Doppler-free spectroscopy on acetylene using synthesized frequencies.
Ahtee
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V
Centre for Metrology and Accreditation, P.O. Box 9, FI-02151 Espoo, Finland. ville.ahtee@mikes.fi
Merimaa
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M
Nyholm
K
K