“…The features of BGO crystal, such as its nonhygroscopic nature, its high electro-optic coefficient, and its easy preparation, make it an ideal crystal for nuclear physics, space physics, nuclear medicine, high-energy physics, and other fields. In early works, BGO waveguides were fabricated by ion implantation and swift ion irradiation [28][29][30][31], and the guiding characteristic and the effect of the annealing treatment were investigated. Fs-laser micromachining was utilized to fabricate waveguides in BGO crystal with a dual-line approach [32].…”