Frequency doubling polymeric waveguide
AssigneeHoechst Celanese Corporation
InventorsGaro Khanarian, David R. Haas
Life of this patent
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Abstract
In one embodiment this invention provides a frequency doubling optical waveguide consisting of a substrate-supported polymeric thin film which exhibits second order nonlinear optical response, and which has a periodic structure for quasi-phase matching of propagating laser wave energy. In a preferred embodiment the waveguide has a two-dimensional channel structure for intensified single mode wave transmission.
Claims23
A nonlinear optical waveguide device for frequency doubling of a 700-1300 nm laser beam which comprises a thin film of a polymeric medium which exhibits second order nonlinear optical response, and which has a spatial periodic structure for quasi-phase matching of propagating wave energy, wherein the coherence length l.sub.c of the periodic polymeric medium is defined by the equation:
- l.sub.c =(.pi./.DELTA..beta.)
- where .DELTA..beta. is the propagation constant difference which is equal to .beta..sub.o (2.omega..sub.1)-2.beta..sub.o (.omega..sub.1), .omega..sub.1 is the fundamental frequency, and subscript zero denotes the zero-ordered mode in the waveguide.
A nonlinear optical waveguide device for frequency doubling of a 700-1300 nm laser beam which comprises a thin film of a polymeric medium which exhibits second order nonlinear optical response, and which has a spatial periodic structure for quasi-phase matching of propagating wave energy;
- wherein the coherence length l.sub.c of the periodic polymeric medium is defined by the equation:
- l.sub.c =(.pi./.DELTA..beta.)
- where .DELTA..beta. is tne propagation constant difference which is equal to .beta..sub.o (2.omega..sub.1)-2.beta..sub.o (.omega..sub.1), .omega..sub.1 is the fundamental frequency, and subscript zero denotes the zero-ordered mode in the waveguide;
- and wherein the polymeric medium comprises a polymer having side chains which exhibit second order nonlinear optical susceptibility and consist of at least 25 weight percent of the polymer, and the side chains have an external field-induced molecular orientation orthogonal to the waveguide plane.
A frequency converting module for producing a short wavelength laser beam which comprises:
- a. a 700-1300 nm laser generating source, in coupled combination with b. an optical waveguide comprising a substrate-supported thin film of a polymeric medium which exhibits second order nonlinear optical response, and which has a spatial periodic structure for quasi-phase matching of propagating wave energy;
- wherein the coherence length l.sub.c of the periodic polymeric medium is defined by the equation:
- l.sub.c =(.pi./.DELTA..beta.)
- where .DELTA..beta. is the propagation constant difference which is equal to .beta..sub.o (2.omega..sub.1)-2.beta..sub.o (.omega..sub.1), .omega..sub.1 is the fundamental frequency, and subscript zero denotes the zero-ordered mode in the waveguide;
- and wherein the polymeric medium comprises a polymer having side chains which exhibit second order nonlinear optical susceptibility and consist of at least 25 weight percent of the polymer, and the side chains have an external field-induced molecular orientation orthogonal to the waveguide plane.
A process for providing a short wavelength laser source which comprises (1) introducing a 700-1300 nm laser beam into an optical waveguide comprising a substrate-supported thin film of a polymeric medium which exhibits second order nonlinear optical response, and which has a spatial periodic structure for quasi-phase matching of propagating wave energy;
- wherein the coherence length l.sub.c of the periodic polymeric medium is defined by the equation:
- l.sub.c =(.pi./.DELTA..beta.)
- where .DELTA..beta. is the propagation constant difference which is equal to .beta..sub.o (2.omega..sub.1)-2.beta..sub.o (.omega..sub.1), .omega..sub.1 is the fundamental frequency, and subscript zero denotes the zero-ordered mode in the waveguide;
- and wherein the polymeric medium comprises a polymer having side chains which exhibit second order nonlinear optical susceptibility and consist of at least 25 weight percent of the polymer, and the side chains have an external field-induced molecular orientation orthogonal to the waveguide plane;
- and (2) doubling the frequency of the propagating wave energy to provide an output 350-650 nm laser beam.
Dependencies are inferred from the claim text.