Thickness variation insensitive frequency doubling polymeric waveguide

• US 5,131,068 A
• Filed: 10/23/1990
• Issued: 07/14/1992
• Est. Priority Date: 10/23/1990
• Status: Expired due to Fees

• Current Assignee: Corning Incorporated
• Original Assignee: Hoechst Celanese Corporation (Sanofi )
• Inventors: Norwood, Robert, Kanarian, Garo
• Primary Examiner(s): Epps, Georgia Y.
• Application Number:
  US07/601,841
• Time in Patent Office: 630 Days
• Field of Search: 372/7, 372/21, 372/22, 385/2, 385/8, 385/14, 385/130, 385/141, 385/122, 359/326-332
• US Class Current: 385/141
• CPC Class Codes: G02F 1/3775 with a periodic structure, e.g. domain inversion, for quasi-phase-matching [QPM] G02F1/383 takes precedence

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 is thickness variation insensitive, and which has a periodic structure for quasi-phase matching of propagating laser wave radiation. In a preferred embodiment the waveguide has a two-dimensional channel structure for intensified single mode wave transmission.

Claims

1. In a method of fabricating a multilayer waveguiding frequency doubler capable of converting a fundamental frequency to its second harmonic frequency which includes providing at least one periodic electrode structure, waveguide and cladding layers and wherein the frequency doubler has a thickness-dependent coherence length, the improvement which comprises providing a waveguiding layer having a thickness at which the derivative of coherence length with respect to thickness is essentially zero.

2. A method in accordance with claim 1 wherein the waveguiding layer is inorganic.

3. A method in accordance with claim 1 wherein the waveguiding layer is lithium niobate.

4. A method in accordance with claim 1 wherein the waveguiding layer is organic.

5. A method in accordance with claim 1 wherein the waveguiding layer is a polymer with an external field-induced noncentrosymmetric molecular orientation of pendant side chains, and the polymer is characterized by a recurring monomeric unit corresponding to the formula:

##STR4## where P'"'"' is a polymer main chain unit, S'"'"' is a flexible spacer group having a linear chain length of between about 2-20 atoms, M'"'"' is a chromophore which exhibits second order nonlinear optical response, and wherein the pendant side chains consist of at least about 10 weight percent of the polymer, and the polymer has a glass transition temperature above about 40°

C.

6. A method in accordance with claim 1 wherein the waveguiding layer has a two-dimensional channel structure for intensified single mode wave transmission.

7. A method in accordance with claim 1 wherein the device is adapted for frequency doubling of a 700-1300 nm laser beam.

8. A method in accordance with claim 1 wherein the device includes a pair of electrodes for the application of an electric field to the waveguide layer.