Figure 1
From: Comb-rooted multi-channel synthesis of ultra-narrow optical frequencies of few Hz linewidth
Comb-rooted optical frequency synthesis. (a) Spectral linewidth vs. tunable range of state-of-the-art continuous-wave lasers; distributed feedback (DFB) lasers, distributed Bragg reflector (DBR) lasers7, external cavity laser diodes (ECLDs)8, linewidth-reduced lasers by optical feedback9,30 and electrical feedback31 are considered here in comparison with the comb-rooted synthesizer developed in this study. (b) Concept of comb-rooted optical frequency synthesis. Multiple frequency modes are extracted concurrently with subsequent conversion to continuous wave lasers to be used for diverse applications. (c) Diode-based stimulated emission by injection locking for power amplification & multi-wavelength comb-rooted synthesis. Abbreviations are; FFP: fiber Fabry-Perot filter, FBG: fiber Bragg grating and OSA: optical spectrum analyzer.
