All-optical heterodyne RF signal generation using a mode-locked-laser frequency comb: theory and experiments

Abstract

Theoretical and experimental investigations are presented for a technique to synthesize signals with high phase stability from 1 GHi to 94 GIEZ by injectiodocking two DFB diode lasers to individual modes of an actively mode-locked laser. An application is demonstrated in a photonic frequencyconverting system at frequencies up to 94 GHZ INTRODUCTION Modulated optical r a d i o -" m y (RF) signals

A Frequency-Doubling Optoelectronic Oscillator Based on a Dual-Parallel Mach–Zehnder Modulator and a Chirped Fiber Bragg Grating

“…The phase noises of the 10 GHz and 20 GHz signals are dBc/Hz and dBc/Hz at 10 kHz frequency offset. The phase noise degradation is 6 dB, which is consistent with the theoretical prediction [16]. In high frequency region (100 kHz-1 MHz), the phase noise degradation is enhanced.…”

Photonic generation of continuous terahertz waves and its application to sensing and communications

“…For 125-GHz signal, the phase noise is approximately -92 dBc/Hz at the offset frequency of 10 kHz, which is larger than that of the 25-GHz RF source by about 13 dB. The result agrees well with the theory regarding phase noise (Phase noise is increased by 20⋅log(m), where m is the multiplication order) [24] and clearly indicates that the optical comb signal is coherent and that the optical filtering process with AWGs and optical switches does not affect the phase noise. According to the results, the estimated phase noises for 300 and 800 GHz at the offset frequency of 10 kHz are -83 and -75 dBc/Hz, respectively.…”

Characterization of a coherent optical RF channelizer based on a diffraction grating

“…A high degree of coherence between the signal beam and the LO comb is required to minimize the phase noise associated with the heterodyne RF signal. Continuous-wave (CW) injection locking of mode-locked lasers has been shown to establish phase coherence between the optical carrier of the signal and the optical frequency comb [9], [10], and we have previously characterized the RF performance of injection locking for this application [11]. The coherent optical channelizer concept is illustrated in Fig.…”