| CPC G02B 6/4239 (2013.01) [G02B 6/4266 (2013.01); H01S 5/02251 (2021.01); H01S 5/02253 (2021.01); H01S 5/0239 (2021.01)] | 20 Claims |
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1. An optical module that transmits emission light emitted by a semiconductor laser through an optical fiber, the optical module comprising:
the semiconductor laser and the optical fiber;
an optical receiver to receive monitor light emitted from an end face opposite to an emission end face from which the emission light is emitted;
a lens to condense the emission light;
a carrier on which the semiconductor laser, the optical receiver, and the lens are mounted; and
a control circuit to control an injection current of the semiconductor laser such that an output current of the optical receiver is kept constant, wherein
the semiconductor laser is fixed on the carrier with a metal bonding material,
the lens and at least a part of the optical receiver are respectively fixed on the carrier with a second resin bonding material and a first resin bonding material that undergo thermosetting shrinkage,
a position of a tip end part of the optical fiber into which the emission light is introduced is fixed with respect to a reference as a rear surface of the carrier opposite to a front surface of a mounting section on which the semiconductor laser, the optical receiver, and the lens are mounted,
an optical coupling efficiency between the semiconductor laser and the optical receiver and an optical coupling efficiency between the semiconductor laser and the optical fiber with respect to an exposure time during which the optical module is exposed to environmental temperature higher than room temperature are referred to as a first optical coupling efficiency characteristic and a second optical coupling efficiency characteristic, respectively, and
initial positions in the semiconductor laser, the tip end part of the optical fiber, the optical receiver, and the lens with respect to the reference as the rear surface of the carrier when the exposure time of the optical module is 0 are determined such that change trends of the first optical coupling efficiency characteristic and the second optical coupling efficiency characteristic are to be the same.
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