Device for excellently coupling a laser beam to a transmission medium through a lens

A device for coupling a laser beam emitted by a laser element to an optical fiber having an end surface, comprising:

• a beam converging lens having an optical axis and responsive to said laser beam for producing a reshaped laser beam;
• a fiber holder having a predetermined axis for holding said optical fiber with said end surface and situated on said predetermined axis;
• a block of a solid material transparent to said reshaped laser beam and having a first and a second surface;
• a mass of a binder transparent to said reshaped laser beam between said second and said end surfaces and between said second surface and said fiber holder;
• a hermetic laser package holding said laser element and having a transparent window opposing said lens;
• a lens holder for holding said lens;
• first fixing means for fixing said lens holder and said fiber holder to each other with said first surface made to receive said reshaped laser beam and with said optical and said predetermined axes substantially aligned;
• and
• second fixing means for fixing said laser package and said lens holder to each other with said reshaped laser beam made to focus substantially on said end surface through said block and said binder mass, wherein said solid material and said binder have refractive indexes that are approximately equal to that of said optical fiber.

A device for coupling a laser beam and having a first beam axis to a transmission medium, comprising:

• a beam converging lens having an optical axis and responsive to said light beam for producing a reshaped laser beam having a second beam axis;
• a hermetic package having a transparent window and a first axial line for holding a semiconductor laser element apart from said transparent window with said first beam axis made to substantially coincide with said first axial line;
• a lens holder having a second axial line and provided with a first opening elongated along said second axial line and a second opening adjacent to said first opening and elongated along said second axial line for holding said lens in said second opening with said optical axis rendered substantially coincident with said second axial line;
• said hermetic package being inserted into said first opening of said lens holder with said first and said second axial lines substantially aligned to couple said reshaped light beam to said transmission medium along said second beam axis.

A device for coupling a laser beam emitted by a semiconductor laser element to an optical fiber having an end surface, comprising:

• a fiber holder having a bore along a predetermined axis;
• an optical fiber having an end surface inserted into said bore with said end surface exposed and situated on said predetermined axis;
• a block of a solid transparent material inserted into said bore having a first and a second surface and refractive index approximately equal to that of said optical fiber, said second surface being disposed adjacent to said end surface;
• a mass of a transparent binder filled into said bore between said second surface and said end surface to fix said block and having refractive index approximately equal to that of said optical fiber;
• a lens holder partly inserted into said bore and having an opening along said predetermined axis;
• a beam converging lens fixed within said opening having third and fourth surfaces, said fourth surface opposing said first surface;
• a hermetic laser package inserted into said opening having a transparent window opposing said third surface;
• and
• a laser element disposed within said hermetic laser package apart from said transparent window so as to pass a laser light through said transparent window along said predetermined axis.

A device for coupling a laser beam emitted by a semiconductor laser element to an optical fiber having an end surface, comprising:

• a fiber holder having a bore along a predetermined axis;
• an optical fiber having an end surface inserted into said bore with said end surface exposed and situated on said predetermined axis;
• a block of a solid transparent material inserted into said bore having a first and a second surface and refractive index approximately equal to that of said optical fiber, said second surface being disposed adjacent to said end surface;
• a mass of a transparent binder filled into said bore between said second surface and said end surface to fix said block and having refractive index approximately equal to that of said optical fiber;
• a lens holder partly inserted into said bore and having an opening along said predetermined axis;
• a beam converging lens fixed within said opening having third and fourth surfaces, said fourth surface opposing said first surface;
• a hermetic laser package inserted into said opening having a transparent window opposing said third surface;
• and
• a laser element disposed within said hermetic laser package apart from said transparent window so as to pass a laser light through said transparent window along said predetermined axis wherein a relationship of said fiber holder, lens holder and hermetic laser package is so determined that said laser light is focused on said end surface of the optical fiber.

A device for coupling a laser beam emitted by a laser element to an optical fiber having an end surface, comprising:

• a fiber holder having a bore along a predetermined axis;
• an optical fiber having an end surface inserted into said bore with said end surface exposed and situated on said predetermined axis;
• a block of a solid transparent material inserted into said bore having a first and a second surface and refractive index approximately equal to that of said optical fiber, said second surface being disposed adjacent to said end surface;
• a mass of a transparent binder filled into said bore between said second surface and end surface to fix said block of solid transparent material and having refractive index approximately equal to that of said optical fiber;
• a lens holder coupled to said fiber holder having an opening along said predetermined axis;
• a beam converging lens fixed within said opening having third and fourth surfaces, said fourth surface opposing said first surface;
• a hermetic laser package coupled to said opening having a transparent window opposing said third surface;
• and
• a laser element disposed within said hermetic laser package apart from said transparent window being so as to pass a laser light through said transparent window along said predetermined axis, wherein said fiber holder, lens holder and hermetic laser holder are fixed to each other so that said laser light is focused on said end surface of the optical fiber.