40nm wavelength tunable gain-switched optical comb source

Abstract

A wavelength tunable optical comb is generated based on the gain-switching of an externally seeded Fabry-Pérot laser diode. The comb consists of about eight clearly resolved 10 GHz coherent sidebands within 3 dB spectral envelope peak and is tunable over the entire C-band (1530 to 1570 nm). The optical linewidth of the individual comb tones is measured to be lower than 100 kHz, and the RIN of the individually filtered comb tones (<-120 dB/Hz) is shown to be comparable to the entire unfiltered comb (<-135 dB/Hz). Besides, expansion of the tunable gain switched comb is achieved with the aid of an optical phase modulator, resulting in near doubling of the number of comb tones.

Simple optical frequency comb generation using a passively mode-locked quantum dot laser

“…However, it needs the optical power beyond 50 W prior to HNLF. Another typical scheme of broadband OFC generation is mainly based on electro-optical modulation, which can be found in [9][10][11][12][13]. In [10], a wavelength tuning range is improved to 40 nm, but the comb lines are not simultaneous and seamless.…”

“…Another typical scheme of broadband OFC generation is mainly based on electro-optical modulation, which can be found in [9][10][11][12][13]. In [10], a wavelength tuning range is improved to 40 nm, but the comb lines are not simultaneous and seamless. In [12], although an OFC with a bandwidth of 10 nm is obtained using a dual-driven Mach-Zehnder modulator (DD-MZM), feedback loops and high quality optical filters are needed.…”

“…Experimentally, we have generated quasi-tunable OFC with frequency intervals of 23.3 GHz, 35 GHz and 70 GHz, which spreads across simultaneous and seamless 86, 56 and 30 comb lines in a 10-dB spectrum bandwidth, respectively. Compared with the reported OFC generators [4][5][6][7][8][9][10][11][12][13], this scheme is not using polarization controllers, optical filters and optical phase lock loops, so it is considered very simple. Using this technique, it is easy to generate quasi-tunable and low phase noise OFCs with seamless broadband and high stability.…”

Effective Phase Noise Suppression in Externally Injected Gain Switched Comb Source for Coherent Optical Communications

“…The potential of this approach lies in its suitability for monolithic integration as well as the flexible tunability in both channel spacing and central wavelength 2,3 . Moreover, it has been shown that external injection effectively transfers the narrow emission linewidth of the injection master to the slave comb lines 2,3 , making such a comb source particularly attractive for coherent applications requiring low linewidth sources.…”

Gain-switched multicarrier transmitter in a long-reach UDWDM PON with a digital coherent receiver

“…Hence, an external cavity laser (ECL) with a linewidth of ∼200 kHz and an output power of 6 dBm was used to inject into the gain switched DFB laser. The external injection from a single low linewidth ECL ensures the transfer of the low linewidth (master) to each of the gain-switched DFB laser (slave) comb tones [10], thereby enabling them to be employed as carriers for advanced modulation format data signals especially at low baud rates (where the linewidth requirement is more stringent). The gain-switched comb source, as illustrated in Fig.…”