An optical apparatus according to an embodiment of the present disclosure is an apparatus that performs one or both of writing and erasing of information with respect to a reversible recording medium. This optical apparatus includes a plurality of laser devices varying in emission wavelength in a near infrared region (700 nm to 2500 nm), an optical system that multiplexes laser beams outputted from the plurality of laser devices, and a scanner unit that scans a multiplexed light beam obtained by multiplexing by the optical system, on the reversible recording medium.