Dual-Frequency Laser at 1.5 \mu m for Optical Distribution and Generation of High-Purity Microwave Signals

• Published in: Journal of lightwave technology Vol. 26; no. 15; pp. 2764 - 2773
• Main Authors: Pillet, G., Morvan, L., Brunel, M., Bretenaker, F., Dolfi, D., Vallet, M., Huignard, J.-P., Le Floch, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.08.2008; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; Delay lines; Delay lock loops; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Frequency; frequency-locked loops; Laser noise; Laser stability; Masers; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; microwave oscillators; Noise measurement; Optical noise; optical phase-locked loops (OPLL); Phase locked loops; Phase measurement; Phase noise; solid-state lasers; Phase noise; optical phase-locked loops (OPLL); solid-state lasers; Stabilization; frequency-locked loops; Optical phase locked loops; Solid state laser; Noise level; Frequency locked loops; delay lines; Noise source; Linear theory; Microwave oscillator; microwave oscillators; Microwave resonator; Delay lock loops; Delay line
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2008.927209

We describe the stabilization of the beatnote of an Er,Yb:glass dual-frequency laser at 1.5 mum with and without an external microwave reference. In the first case, a classical optical phase-locked loop (OPLL) is used, and absolute phase noise levels as low as -117 dBrad 2 /Hz at 10 kHz from the carrier are reported. In the second case one or two fiber-optic delay lines are used to lock the frequency of the beatnote. Absolute phase noise levels as low as -107 dBrad 2 /Hz at 10 kHz from the carrier are measured, fairly independant of the beatnote frequency varying from 2 to 6 GHz. An analysis of the phase noise level limitation is presented in the linear servo-loop theory framework. The expected phase noise level calculated from the measurement of the different noise sources fits well with the predictions.