An optical module includes a light-forming unit to form light. The light-forming unit includes a base member having an electronic temperature control module, a base plate, a plurality of submounts, and a microelectromechanical system (MEMS) base. The light-forming unit also includes a plurality of laser diodes arranged on the submounts, a filter arranged on the base plate and located to receive the light emitted from the plurality of laser diodes and multiplex the emitted light, a MEMS arranged on the MEMS base and located to receive the light multiplexed by the filter. The MEMS includes a scanning mirror to scan the light multiplexed by the filter, and the electronic temperature control module regulates a temperature range of the MEMS. The light-forming unit also includes a protective member surrounding and sealing the light-forming unit, which includes a base body and a lid welded to the base body.