Tunable laser and manufacturing method for tunable laser

A wavelength tunable laser, comprising:

• a substrate layer;
• a support layer disposed above the substrate layer and having a protection structure;
• a transport layer disposed above the support layer and comprising a lower cladding layer, a waveguide layer and an upper cladding layer, wherein the protection structure forms a hollow structure together with the transport layer and the substrate layer, and the hollow structure includes a support structure;
• a heating layer disposed above the transport layer;
• and
• a reflector disposed in the transport layer;
• wherein:
• in a first direction, there are gaps between a part, comprising the reflector, of the transport layer and materials on two sides of the transport layer, to form a suspended structure,
• within a length range of the reflector in the first direction, the gaps are configured to isolate the suspended structure from the materials on the two sides of the transport layer, so that the suspended structure is not connected to the materials on the two sides of the transport layer,
• the first direction is a transmission direction of light in the waveguide layer, and
• the suspended structure has a varying width in the first direction;
• and
• wherein the support structure comprises:
• a first support structure disposed below a wider part of the suspended structure;
• a second support structure disposed below a narrower part of the suspended structure;
• and
• wherein the first support structure is larger than the second support structure.

A method of manufacturing a wavelength tunable laser, the method comprising:

• forming a substrate layer;
• forming a support layer above the substrate layer;
• removing a portion of the support layer to form a protection structure;
• forming a transport layer above the support layer, the transport layer comprising an lower cladding layer, a waveguide layer and an upper cladding layer, wherein the protection structure forms a hollow structure together with the transport layer and the substrate layer, and the hollow structure comprises a support structure within a hollow area of the hollow structure between the lower cladding layer of the transport layer and the substrate layer, wherein gaps formed between the support structure and the protection structure are configured to insulate heat to increase heat acting on a reflector;
• depositing a heating layer above the transport layer;
• and
• forming the reflector in the transport layer;
• wherein:
• in a first direction, there are gaps formed between a part, comprising the reflector, of the transport layer and materials on two sides of the transport layer, to form a suspended structure,
• within a length range of the reflector in the first direction, the formed gaps are configured to isolate the suspended structure from the materials on the two sides of the transport layer, so that the suspended structure is not connected to the materials on the two sides of the transport layer,
• the first direction is a transmission direction of light in the waveguide layer, and
• the suspended structure has a varying width in the first direction;
• and
• wherein the support structure comprises:
• a first support structure formed below a wider part of the suspended structure;
• a second support structure formed below a narrower part of the suspended structure;
• and
• wherein the first support structure is larger than the second support structure.