We propose a novel scheme for the expansion and comb densification of gain-switched
optical frequency combs (GS-OFC). The technique entails mutual injection locking of two gainswitched lasers with a common master to generate a wider bandwidth OFC. Subsequently, the OFC
is further expanded and/or densified using a phase modulator with optimum drive conditions. We
experimentally demonstrate the generation of an OFC with 45 highly correlated lines separated by
6.25 GHz with an expansion factor ~3. In addition, operating in comb densification mode, the channel
spacing of the OFC is tuned from 6.25 GHz to 390.625 MHz. Finally, a detailed characterization of
the lines, across the entire expanded comb, is reported highlighting the excellent spectral purity
with linewidths of ~40 kHz, a relative intensity noise better than −152 dB/Hz, and a high degree of
phase correlation between the comb lines. The proposed method is simple, highly flexible and the
architecture is suitable for photonic integration, all of which make such an OFC extremely attractive
for the employment in a multitude of applications.
Metadata
Item Type:
Article (Published)
Refereed:
Yes
Additional Information:
Article number: 7108
Uncontrolled Keywords:
optical frequency comb; gain-switched laser; mutually injection-locked lasers
Science Foundation Ireland’s(SFI) career development award(15/CDA/3640), Science Foundation Ireland RDF(13/RC/2077_P2)., EnterpriseIreland DTIF(DT20180268)
ID Code:
27068
Deposited On:
27 Apr 2022 09:46 by
Pascal Landais
. Last Modified 22 Aug 2022 15:53