A low phase noise optical link for reference oscillator signal distribution

Evaluation of low cost solutions for the transmission through optical fiber of low phase noise OCXO signals

“…This signal is generally provided in a system by an oven controlled crystal oscillator (OCXO). The transmission of high spectral purity signals using fiber optics links has been described in many papers [1][2][3][4][5], and particularly the classical approach in which the reference signal directly modulates the current of a medium power DFB laser. The phase noise floor, for this type of link, is mainly related to the laser relative intensity noise (RIN) and the laser modulation index m, at least for a point to point link (m = P P Δ , with P being the average optical power and ΔP the maximum deviation from P due to the modulation; m ≤ 1).…”