| 摘要 |
<p>A system and method are provided for writing refractive index structures, such as gratings, in an optical waveguide. There is no requirement for structures having interferometric stability of the control elements. The method includes providing first and second light beams, the first beam having a first polarization state and a first wavevector, the second beam having a second polarization state different from the first polarisation state, and a second wavevector different from the first wavevector. The method also includes illuminating a diffractive optical element by at least a part of the first beam and a part of the second beam so as to diffract parts of the first and second beams, and positioning the medium in relation to the diffractive element so as to illuminate the first part of the medium by the diffracted parts of the first and second beams.</p> |
