Optical Frequency Comb with Broadly Tunable Spacing Generation with Achromatic Wide-Angle Acousto-Optic Diffraction in LiNa5Mo9O30 Biaxial Crystal

In this work, we investigate the possibility of wide-aperture acousto-optic (AO) interaction geometry in a rhombic LiNa
5
Mo
0
O
30
(LNM) crystal application for optical frequency comb (OFC) synthesis in a scheme with the optical feedback loop containing an AO cell. The spectral bandwidth and frequency range of LNM based AO cells utilizing various regimes of such interaction geometry implemented in the plane of optical axes are calculated. The main attention is paid to the achromatic wide-angle diffraction mode. The span of the combs generated with similar $A O$ interaction mode, as well as the tuning interval of its spacing, is estimated. The prospects of the LNM crystal for OFC with tunable spacing synthesis in the telecom C-band are proved.