Patent ID: 7031567

Claim:
A method of coupling a high-power optical signal between an optical fiber and a mating optical component, said optical signal ranging in wavelength from x to y, and having a first diameter while propagating in a mode field within said fiber, said method comprising: converting said high-power optical signal between said first diameter in said fiber and a second diameter significantly greater than said first diameter using a GRIN lens fused to an end of the said fiber, said GRIN lens having a diameter substantially the same as that of said optical fiber and a length l complying with the following equation: ¼ x+ ½ nx≦l ≦¼ y +½ ny, wherein n=0, 1, 2, 3 . . . 100; establishing physical contact at the interface of said GRIN lens and a coupling surface of said mating optical component; and while said high-power optical signal is at said second diameter, optically coupling it between said GRIN lens and said mating optical component.