Fig. 1. Schematic of integrated LNPhC devices, including wavelength converter, sensor, modulator, opto-mechanical cavity, and superprism.

Fig. 2. Schematic of (a) TF-LNPhC on silica. Adapted with permission from [20]. (b) Suspended LNPhC. Adapted with permission from [22]. (c) APE LNPhC on common LN with lateral confinement. Adapted with permission from [15].

Fig. 3. Schematic of the LNPhC fabricated by EBL with Ar⁺ etching. (a) 2D LNPhC cavity. Adapted with permission from [28]. (b) LNPhC cavity with ultra-high Q-factor. Adapted with permission from [29]. (c) LNPhC modulator. Adapted with permission from [30].

Fig. 4. (a) Fabrication procedures of LNPhC based on the reactive ion etching and the IBEE technique. Adapted with permission from [10] and [25]. (b) Fabrication procedure of LNPhC based on redeposition-free FIB technique. Adapted with permission from [42]. (c) SEM image of holes fabricated by IBEE technique and redeposition-free FIB technique. Adapted with permission from [10] and [42].

Fig. 5. (a) Schematic and (b) SEM image of the etchless LNPhC with silica as the mask. Adapted with permission from [43]. (c) Schematic and (d) SEM image of the etchless LNPhC with polymer as the mask. Adapted with permission from [44].

Fig. 6. (a) Schematic of tapered fiber coupling. Adapted with permission from [28]. (b) End-face coupling. Adapted with permission from [15]. (c) Cross-polarized resonant scattering coupling. Adapted with permission from [38]. (d) Grating coupling. Adapted with permission from [34].

Fig. 7. (a), (b) Optical microscopy images of two different mode-gap cavities. (c) Spectrum of the second-harmonic signal of the mode-gap cavity. (d) Second-harmonic power as a function of the fundamental pump wave power of the mode-gap cavity. Adapted with permission from [28]. (e) Second-harmonic power as a function of the fundamental pump wave power of the L3 cavity. Adapted with permission from [38]. (f) Second-harmonic power as a function of the fundamental pump wave of the bulk cavity made by redeposition-free FIB. Adapted with permission from [42].

Fig. 8. (a) Schematic of the LNPhC waveguide used for generating spectrally unentangled biphoton states. Mode profiles of pump, signal, and idler modes at the (b) z = 0 and (c) y = 0 planes. (d) Band diagram of the pump mode. (e) Band diagram of the signal and idler modes. (f) Bloch harmonic distribution of the modes. Adapted with permission from [68].

Fig. 9. (a) SEM image, (b) experimental setup, and (c) results for Fano resonance-based LNPhC sensor. Adapted with permission from [75]. (d) Simulated transmission of the BIC LNPhC sensor. Adapted with permission from [80].

Fig. 10. (a) Structure and (b) SEM image and enlarged SEM image of the mode-gap LNPhC modulator. (c) Eye diagrams of the electro-optic switch. Adapted with permission from [30].

Fig. 11. (a) SEM image of suspended LNPhC nanobeam and (b) observed mechanical lasing. Adapted with permission from [31]. (c) SEM image of the LNPhC transducer. Adapted with permission from [33]. (d) Transmission spectrum and power spectral density change for the mechanical mode. Adapted with permission from [54].