Method for the manufacture of a waveguide mixer
AssigneeGEC-Marconi Limited
InventorsMark Farries, Luksun Li, Martin Fermann, David Payne
Life of this patent
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Abstract
A method is presented for writing a permanent spatially periodic phase-matching second-order non-linearity grating in an optical waveguide. Single frequency exciting radiation is launched in a pair of guided modes of the waveguide in the presence of an external DC electric field applied in a direction transverse to the waveguide. The exciting radiation may be either co-propagating or counter-propagating. The above method may be refined by performing it once for an estimated value of exciting radiation frequency, testing the waveguide to determine error in the chosen estimate, erasing the grating and re-performing the method using a corrected value for the frequency of the exciting radiation.
Claims13
A method of manufacturing a waveguide mixer comprising the steps of:
- providing a waveguide, which waveguide incorporates a multiplicity of excitable defect centres and is capable of sustaining a plurality of guided modes;
- launching through the waveguide an exciting radiation of a predetermined single frequency in at least two guided modes within the waveguide in the absence of an exciting radiation other than said single frequency;
- and
- applying simultaneously with propagation of the exciting radiation in said at least two guided modes, an external dc electric field transverse to the waveguide, thereby to produce in the waveguide a permanent spatially-periodic phase-matching second-order non-linearity grating.
A method of manufacturing a waveguide mixer comprising the steps of:
- (A) providing a waveguide, which waveguide incorporates a multiplicity of excitable defect centres and is capable of sustaining a plurality of guided modes;
- (B) pre-treating the waveguide to enhance concentration of the excitable defect centres by carrying out one of the following treatments:
- (a) high energy radiation,
- (b) exposure to hydrogen gas under elevated pressure,
- (c) production in oxygen starved ambient, and
- (d) addition of a defect promoting dopant;
- (C) launching through the pretreated waveguide, an exciting radiation of a predetermined single frequency in at least two guided modes within the waveguide in the absence of an exciting radiation other than said single frequency;
- and
- (D) applying simultaneously with propagation of the exciting radiation in said at least two guided modes, an external dc electric field transverse to the waveguide, thereby to produce in the waveguide a permanent spatially-periodic phase-matching second-order non-linearity grating.
Dependencies are inferred from the claim text.