Optical device, optical transmitting apparatus, and optical receiving apparatus

An optical transmitting apparatus comprising:

• a processor that performs signal processing for an electrical signal;
• a light source that generates light;
• and
• an optical transmitter that modulates light generated from the light source by using the electrical signal outputted from the processor, wherein
• an optical device in the optical transmitter includes:
• a lower cladding formed on a substrate;
• a core formed on the lower cladding;
• and an upper cladding covering the core,
• the optical device includes:
• a first channel waveguide;
• a second channel waveguide connected to the first channel waveguide;
• a slab generator connected to the second channel waveguide;
• and
• a rib waveguide connected to the slab generator, wherein
• the second channel waveguide includes a first connection connected to the first channel waveguide and a second connection connected to the slab generator, and the second channel waveguide is wider at the second connection than at the first connection,
• a slab region of the slab generator includes a third connection connected to the rib waveguide and widens from the second connection of the second channel waveguide toward the third connection,
• effective refractive indexes of waveguide modes at the first connection are larger in an order of Transverse Electric (TE) 0, Transverse Magnetic (TM) 0, and TE1,
• effective refractive indexes of the waveguide modes at the second connection are larger in an order of TE0, TE1, and TM0, and
• effective refractive indexes of the waveguide modes at the third connection are larger in an order of TE0, TE1, and TM0.

An optical receiving apparatus comprising:

• a light source that generates light;
• and
• an optical receiver that demodulates received light by using the light from the light source, wherein
• an optical device in the optical receiver includes:
• a lower cladding formed on a substrate;
• a core formed on the lower cladding;
• and an upper cladding covering the core,
• the optical device includes:
• a first channel waveguide;
• a second channel waveguide connected to the first channel waveguide;
• a slab generator connected to the second channel waveguide;
• and
• a rib waveguide connected to the slab generator,
• the second channel waveguide includes a first connection connected to the first channel waveguide and a second connection connected to the slab generator, and the second channel waveguide is wider at the second connection than at the first connection,
• a slab region of the slab generator includes a third connection connected to the rib waveguide and widens from the second connection of the second channel waveguide toward the third connection,
• effective refractive indexes of waveguide modes at the first connection are larger in an order of Transverse Electric (TE) 0, Transverse Magnetic (TM) 0, and TE1,
• effective refractive indexes of the waveguide modes at the second connection are larger in an order of TE0, TE1, and TM0, and
• effective refractive indexes of the waveguide modes at the third connection are larger in an order of TE0, TE1, and TM0.