An optical module 1 comprises a first optical element F1, a first light
receiving subassembly PD1, a second optical element F2, a second light
receiving subassembly PD2, a light emitting subassembly LD3 for
generating light, and a light transmitting part 3 optically coupled to
the first optical element. The light emitting subassembly LD3, the first
optical element F1, the second optical element F2 and the first light
receiving subassembly PD1 are arranged along a predetermined plane S1.
The light emitting subassembly LD3, the first optical element F1, the
second optical element F2, and the second light receiving subassembly PD2
are arranged along another predetermined plane S2. The predetermined
plane S1 intersects at a predetermined angle with the other predetermined
plane S2.