Terahertz span >60-channel exact frequency dense WDM source using comb generation and SG-DBR injection-locked laser filtering

Phase discrimination and simultaneous frequency conversion of the orthogonal components of an optical signal by four-wave mixing in an SOA

“…The pump comb may either be derived from a mode-locked laser, as in the experiment described above, or alternatively obtained by RF modulation of a CW source [15,16]. Narrower linewidths are normally achievable with the latter technique.…”

High‐power RF photodiodes and their applications

“…The selection and combination of two modes corresponds to frequency multiplication, Nf 0 . The fundamental frequency, f 0 , is usually 10 to 30 GHz, where optical modulators and driver electronics are commercially available, and the multiplication factor can be made over 50 [22,[25][26][27]. Since fine and accurate tuning off 0 is possible by using a synthesized signal generator, we can continuously change the frequency from f 0 to Nf 0 .…”

“…2b shows another optical heterodyning technique which can generate extremely low-phase-noise signals [17][18][19][20][21]. Key components are an optical frequency comb generator (OFCG), which generates multi-frequency (wavelength) optical signals [22][23][24][25], and an optical filter, which selects two of these. Typical OFCGs are mode-locked short-pulse lasers, and a combination of a single-mode laser and optical amplitude and/or phase modulators.…”

Nanosecond Channel-Switching Exact Optical Frequency Synthesizer Using an Optical Injection Phase-Locked Loop (OIPLL)

“…In this letter, we report experimental results for a novel rapid channel-switching dense wavelength-division-multiplexing (DWDM) synthesizer system whose channel frequency is determined by the supplied optical and microwave reference frequencies [7], combining the advantages of a highly stable and widely tuneable system with fast wavelength switching. By using an atomic transition-locked optical reference, each channel can have an absolute frequency error 20 kHz [8], while the channel frequency spacing is determined by the stability of the microwave reference.…”

“…The optical frequency comb generator (OFCG) uses an amplified fiber loop with an embedded phase modulator. The loop, operated as a resonant cavity, multiplies the number of equally spaced side-frequencies produced by the phase modulator, driven by a microwave synthesizer ( GHz) and generates over 100 comb lines after recirculation [7]. The referenced comb spectrum was delivered to a number of channel (slave) lasers in optical injection phase-locked loop (OIPLL) blocks, which were locked to selected lines.…”