Harmonic generation using optimized stack of thin films

Patent metadata

Field	Value
Publication number	US-9880445-B1
Application number	US-201514744909-A
Country	US
Kind code	B1
Filing date	Jun 19, 2015
Priority date	Jun 19, 2015
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

Systems and methods implementing a stack on a substrate, where the stack includes a plurality of films structured as layers to convert radiation incident to the stack to radiation of a nonlinear optical signal different from the incident radiation or to a harmonic of the incident radiation, can be used in a variety of applications. The stack can be structured having parameters selected with respect to conversion efficiency and bandwidth the converted radiation. Additional systems and methods can be used in a variety of applications.

First claim

What is claimed is:

1. An apparatus comprising:
a substrate; and
a plurality of films on the substrate, the plurality of films structured in a stack, the stack arranged to receive radiation, the radiation including radiation at one or more frequencies, and structured to convert the radiation incident to the stack to radiation of a nonlinear optical signal different from the incident radiation, wherein each film of the plurality of films contributes to the nonlinear optical signal such that the nonlinear optical signal from the stack at one or more frequencies is larger than a sum of the corresponding nonlinear signal intensities from each film through a combination of field enhancement in the films and global phase mismatch compensation.

2. The apparatus of claim 1 , wherein the stack is structured with respect to incident radiation being at one frequency and the radiation produced from the conversion consisting of radiation of several frequency components, the sum of the several frequency components equaling the frequency of the incident radiation.

3. The apparatus of claim 1 , wherein the stack is structured with respect to incident radiation including the mixing of a plurality of optical waves.

4. The apparatus of claim 1 , wherein the stack is structured to maximize output amplitude and optimize bandwidth and phase behavior of the converted radiation.

5. The apparatus of claim 1 , wherein the stack is structured with respect to incident radiation having several frequency components and the radiation produced from the conversion is radiation of one frequency, the one frequency being a sum of the several frequency components of the incident radiation.

6. The apparatus of claim 1 , wherein the stack is structured with respect to incident radiation of one frequency that produces output at a higher harmonic of the one frequency.

7. The apparatus of claim 1 , wherein the radiation produced from the conversion includes radiation of a higher harmonic than radiation at a second harmonic.

8. An apparatus comprising:
a substrate; and
a plurality of films on the substrate, the plurality of films structured in a stack, the stack arranged to receive radiation, the radiation being at a frequency, and structured to convert the radiation incident to the stack to radiation at an integer multiple of the frequency by use of nonlinear optical harmonic generation based on the stack, wherein each film of the plurality of films contributes to the nonlinear optical signal such that the nonlinear optical signal from the stack is larger than a sum of the nonlinear signal intensities from each film through a combination of field enhancement in the films and global phase mismatch compensation.

9. The apparatus of claim 8 , wherein the radiation at the integer multiple of the frequency is a directly generated third harmonic of the frequency.

10. The apparatus of claim 8 , where the harmonic is a fifth harmonic of the frequency.

11. The apparatus of claim 8 , wherein the plurality of films includes a set of silica films disposed in the stack such that each silica film is located between two dielectric films of the plurality of films other than silica.

12. The apparatus of claim 8 , wherein each film of the plurality of films has a thickness optimized with respect to conversion efficiency, bandwidth, and/or phase of the radiation at the integer multiple of the frequency.

13. The apparatus of claim 8 , wherein the plurality of films includes one of more of hafnia, Hf x Si 1-x O 2 with 0<x<1, alumina, or scandia.

14. The apparatus of claim 8 , wherein the stack is structured to produce the harmonic in reflection from the stack.

15. The apparatus of claim 8 , wherein the stack is structured to produce the harmonic in transmission through the stack.

16. A system comprising:
an optical source, the optical source being one or more lasers operable to provide one or more laser frequencies; and
an apparatus including:
a substrate; and
a plurality of films on the substrate, the plurality of films structured in a stack, the stack arranged to receive radiation, the radiation including radiation at one or more frequencies, and structured to convert the radiation incident to the stack to radiation of a nonlinear optical signal different from the incident radiation, wherein each film of the plurality of films contributes to the nonlinear optical signal such that the nonlinear optical signal from the stack at one or more frequencies is larger than a sum of the corresponding nonlinear signal intensities from each film through a combination of field enhancement in the films and global phase mismatch compensation.

17. The system of claim 16 , wherein the stack is structured with respect to incident radiation being at one frequency that produces output at a higher harmonic of the one frequency.

18. The system of claim 16 , wherein the stack is structured with respect to incident radiation including the mixing of a plurality of optical waves.

19. The system of claim 16 , wherein the stack is structured to maximize output amplitude and optimize bandwidth and phase behavior of the converted radiation.

20. The system of claim 16 , wherein the optical source is arranged to provide laser radiation to the stack at a fundamental frequency, the stack arranged to receive the laser radiation from the optical source at the fundamental frequency and structured to convert the laser radiation incident to the stack to radiation at an integer multiple of the fundamental frequency by use of nonlinear optical harmonic generation based on the stack, the stack having parameters selected with respect to conversion efficiency and bandwidth of a directly generated harmonic of the fundamental frequency.

21. The system of claim 20 , wherein the parameters are related to conversion efficiency, and bandwidth and phase of a directly generated third harmonic of the fundamental frequency.

22. The system of claim 20 , where the harmonic is a fifth harmonic.

23. The system of claim 20 , wherein the plurality of films includes a set of silica films disposed in the stack such that each silica film is located between two dielectric films of the plurality of films other than silica.

24. The system of claim 20 , wherein each film of the plurality of films has a thickness optimized with respect to conversion efficiency, bandwidth, and/or phase of the radiation at the integer multiple of the fundamental frequency.

25. The system of claim 20 , wherein the plurality of films includes one of more of hafnia, Hf x Si 1-x O 2 with 0<x<1, alumina, or scandia.

26. The system of claim 20 , wherein the stack is structured to produce the harmonic in reflection from the stack.

27. The system of claim 20 , wherein the stack is structured to produce the harmonic in transmission through the stack.

28. The system of claim 20 , wherein the laser is a femtosecond laser.

29. A method comprising:
determining, in a processing system having a processor and a memory module, a number of layers of films and materials of the films for a stack disposed on a substrate, the stack structured to convert radiation incident to the stack to radiation of a nonlinear optical signal different from the incident radiation, the number of layers of films being a plurality of films and the radiation incident to the stack including radiation at one or more frequencie

Assignees

• Stc Unm

Inventors

• Rudolph Wolfgang G
• Rodriguez Cristina

Classifications

• G02F1/37 Primary

  for second-harmonic generation {(G02F1/3532 takes precedence)} · CPC title

• H01S3/0092

  Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35) · CPC title

• G02F1/3544

  Particular phase matching techniques · CPC title

• G02F1/354

  Third or higher harmonic generation · CPC title

• G02F1/3548

  Quasi phase matching [QPM], e.g. using a periodic domain inverted structure · CPC title