Patent ID: 7095931
Filing Date: 2006-08-22
Classification: C03C,G02B

Abstract:
1. A method for creating an optical waveguiding device from an elongated generally annular optical fiber made of glass material and having at least one core and at least one cladding by creating a zone of permanently altered refractive index characteristics in the optical fiber, using a focused beam which is generated by a pulsed laser light source having: (i) a wavelength greater than the absorption edge of the glass material; (ii) a pulse width of less than 1 picosecond, and a pulse energy of between 1 nanojoule and 1 millijoule; and (iii) capable of achieving a peak pulse intensity within a defined focal region; (a) aligning said laser beam focal region with a defined target region within the optical fiber, said target region extending through the core and at least partially through the cladding of the optical fiber, at an acute angle to a longitudinal axis thereof; (b) providing relative movement between said optical fiber and said beam such that said laser beam focal region sweeps along said target region; and (c) operating said laser light source with the peak pulse intensity thereof and a repetition rate thereof selected to accumulate heat and to soften the glass material within the target region and to thereby induce permanent refractive index changes in the optical fiber within the target region; said optical waveguiding device exhibiting controlled polarization sensitivity.