[1] HECK M J R, BAUTERS J F, DAVENPORT M L et al. Ultra-low loss waveguide platform and its integration with silicon photonics[J]. Laser & Photonics Reviews, 8, 667-686(2014).

[2] XIAO P, WANG B. Design of an erbium-doped Al2O3 optical waveguide amplifier with on-chip integrated laser pumping source[J]. Optics Communications, 508, 127709(2022).

[3] CHEN Ziping, SHU Haowen, WANG Xingjun. The latest research progress of silicon-based integrated optical waveguide amplifier[J]. Science China Physics, Mechanics & Astronomy, 47, 5-23(2017).

[4] VÁZQUEZ-CÓRDOVA S A, DIJKSTRA M, BERNHARDI E H et al. Erbium-doped spiral amplifiers with 20 dB of net gain on silicon[J]. Optics Express, 22, 25993-26004(2014).

[5] SUBRAMANIAN A Z, MURUGAN G S, ZERVAS M N et al. High index contrast Er: Ta2O5 waveguide amplifier on oxidized silicon[J]. Optic Communications, 285, 124-127(2012).

[6] FRANKIS H C, MBONDE H M, BONNEVILLE D B et al. Erbium-doped TeO2-coated Si3N4 waveguide amplifiers with 5 dB net gain[J]. Photonics Research, 8, 127-134(2020).

[7] DEMIRTAS M, ODACI C, PERKGOZ N K et al. Low loss atomic layer deposited Al2O3 waveguides for applications in on-chip optical amplifiers[J]. IEEE Journal of Selected Topics in Quantum Electronics, 24, 3100508(2018).

[8] LI N, MAGDEN E S, SINGH G et al. Ultra-narrow-linewidth Al2O3:Er3+ lasers with a wavelength-insensitive waveguide design on a wafer-scale silicon nitride platform[J]. Optics Express, 25, 13705-13713(2017).

[9] BRADLEY J D B, AGAZZI L, GESKUS D et al. Integrated Al2O3:Er3+ ring lasers on silicon with wide wavelength selectivity[J]. Optic Letters, 35, 73-75(2010).

[10] PING L K, BERHANUDDIN D D, MONDAL A K et al. Properties and perspectives of ultrawide bandgap Ga2O3 in optoelectronic applications[J]. Chinese Journal of Physics, 73, 195-212(2021).

[11] PEARTON S J, YANG J, CARY P H et al. A review of Ga2O3 materials, processing, and devices[J]. Applied Physics Reviews, 5, 011301(2018).

[12] DAKHEL A A. Investigation of opto-dielectric properties of Ti-doped Ga2O3 thin films[J]. Solid State Sciences, 20, 54-58(2013).

[13] ONUMA T, FUJIOKA S, YAMAGUCHI T et al. Correlation between blue luminescence intensity and resistivity in β-Ga2O3 single crystals[J]. Applied Physics Letters, 103, 041910(2013).

[14] WANG R, YAN K, ZHANG M et al. Chemical environment of rare earth ions in Ge28.125Ga6.25S65.625 glass-ceramics doped with Dy3+[J]. Applied Physics Letters, 107, 161901(2015).

[15] REBIEN M, HENRION W, HONG M et al. Optical properties of gallium oxide thin films[J]. Applied physics letters, 81, 250-252(2002).

[16] GHOSE S, RAHMAN M S, ROJAS-RAMIREZ J S et al. Structural and optical properties of β-Ga2O3 thin films grown by plasma-assisted molecular beam epitaxy[J]. Journal of Vacuum Science & Technology B, Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena, 34, 02L109(2016).

[17] LIANG H W, CHEN Y P, XIA X C et al. A preliminary study of SF6 based inductively coupled plasma etching techniques for beta gallium trioxide thin film[J]. Materials Science in Semiconductor Processing, 39, 582-586(2015).

[18] MUTTALIB M F A, CHEN R Y, PEARCE S J et al. Optimization of reactive-ion etching (RIE) parameters for fabrication of tantalum pentoxide (Ta2O5) waveguide using Taguchi method[J]. EPJ Web of Conferences, 162, 01003(2017).

[19] GARCÍA-VALENZUELA J A, RIVERA R, MORALES-VILCHES A B et al. Main properties of Al2O3 thin films deposited by magnetron sputtering of an Al2O3 ceramic target at different radio-frequency power and argon pressure and their passivation effect on p-type c-Si wafers[J]. Thin Solid Films, 619, 288-296(2016).

[20] LI C, GUO P, HUANG W et al. Reverse-strip-structure Ge28Sb12Se60 chalcogenide glass waveguides prepared by micro-trench filling and lift-off[J]. Journal of the Optical Society of America B, 37, 82(2019).

[21] SAIKUMAR A K, NEHATE S D, SUNDARAM K B. Review—RF sputtered films of Ga2O3[J]. ECS Journal of Solid State Science and Technology, 8, Q3064-Q3078(2019).

[22] SINGH A K, GUPTA M, SATHE V et al. Effect of annealing temperature on β-Ga2O3 thin films deposited by RF sputtering method[J]. Superlattices and Microstructures, 156, 106976(2021).

[23] HOGAN J E, KAUN S W, AHMADI E et al. Chlorine-based dry etching of β-Ga2O3[J]. Sciences Technology, 31, 065006(2016).

[24] SHAHA A P, BHATTACHARYA A. Inductively coupled plasma reactive-ion etching of β-Ga2O3: Comprehensive investigation of plasma chemistry and temperature[J]. Journal Vacuum Science & Technology A, 35, 041301(2017).

[25] LU R, LINK S, ZHANG S et al. Aluminum nitride lamb wave delay lines with Sub-6 dB insertion loss[J]. Journal of Microelectromechanical Systems, 28, 569-571(2019).

[26] CHOI C G, HAN Y T, KIM J T et al. Air-suspended two-dimensional polymer photonic crystal slab waveguides fabricated by nanoimprint lithography[J]. Applied Physics Letters, 90, 221109-221112(2007).