Wavelength division multiplexed coupler

An optical device includes a plurality of optical parts for processing an optical signal transmission therein, comprising:

• a plurality of gaps each having an adjusted distance between said plurality of optical parts;
• two holding tubes holding two of said plurality of optical parts and said holding tubes are in contact with each other in at least one of said gaps;
• and
• an epoxy applied over contact area between two of said holding tubes over one of said gaps for securely bonding said holding tubes holding said plurality of optical parts.

A method for fabricating a WDM coupler comprising steps of

• a) attaching a WDM filter to a first GRIN lens by applying a first heat-curing epoxy;
• b) inserting and fixing said first GRIN lens attached to said WDM filter into a first holding tube by applying a second heat-curing epoxy;
• c) inserting a dual fiber pigtail into a second holding tube then adjusting a relative position between said dual fiber pigtail and said first GRIN lens on an alignment stage to achieve a lowest reflection loss;
• d) sliding said second holding tube along said dual fiber pigtail without moving said dual fiber pigtail until said first and second holding tubes are in contact then fixing said first and second holding tubes and said dual fiber pigtail together by applying a third heat curing epoxy;
• e) inserting and fixing a second GRIN lens into a third holding tube by applying a fourth heat-curing epoxy;
• f) mounting said third holding tube with said second GRIN lens on an alignment stage then inserting a single fiber pigtail into said third holding tube and adjusting and fixing said single fiber pigtail to an optimal position in said third holding tube from said second GRIN lens by applying a fifth heat-curing epoxy;
• g) adjusting a relative position of said first GRIN lens to said second GRIN lens until both a lowest overall transmission loss is achieved with said first and third holding tubes in contact;
• and
• h) fixing said first and third holding tubes together by applying a sixth heat-curing epoxy.

A method for fabricating an optical device includes a plurality of optical parts for processing an optical signal transmission therein, comprising steps of:

• a) inserting said plurality of optical parts into holding tubes and arranging and adjusting said plurality of optical parts having an optimal position from each other;
• b) applying an epoxy for bonding said optical parts in said holding tubes;
• c) sliding said holding tubes toward a gap between each of said optical parts and having edges contacting each other;
• and
• d) applying an epoxy for bonding said optical parts to said holding tubes and bonding said holding tubes together.