High-order harmonic wave generation apparatus capable of selecting wavelength

Patent metadata

Field	Value
Publication number	US-9620927-B2
Application number	US-201615063834-A
Country	US
Kind code	B2
Filing date	Mar 8, 2016
Priority date	Aug 13, 2015
Publication date	Apr 11, 2017
Grant date	Apr 11, 2017

Abstract

A high-order harmonic wave generation apparatus using a diode-pumped solid state laser includes a pump head for generating a fundamental wave, Porro prisms disposed on the left and right sides of the pump head, nonlinear crystals for sequentially generating a second-order harmonic wave, a fourth-order harmonic wave, and a fifth-order harmonic wave from the fundamental wave, and a final emission unit for reflecting and transmitting any one of the second-order harmonic wave, the fourth-order harmonic wave, and the fifth-order harmonic wave and for emitting the harmonic wave without changing the optical path. Accordingly, the apparatus is insensitive to changes in the external environment through a resonator having a structure comprising Porro prisms, and enables the final emission unit to selectively output the fourth-order harmonic wave or the fifth-order harmonic wave.

First claim

What is claimed is:

1. A high-order harmonic wave generation apparatus for selecting a wavelength, comprising:
Porro prisms, arranged on a left side and a right side of a pump head in order to make a fundamental wave, generated by the pump head, insensitive to a change in an external environment;
nonlinear crystals for sequentially generating a second-order harmonic wave, a fourth-order harmonic wave, and a fifth-order harmonic wave from the fundamental wave; and
final emission units for reflecting and transmitting the second-order harmonic wave, the fourth-order harmonic wave, and the fifth-order harmonic wave and for emitting the harmonic wave without changing an optical path,
wherein the nonlinear crystals comprise a second-order harmonic wave generation nonlinear crystal for generating the fundamental wave and the second-order harmonic wave, a fourth-order harmonic wave generation nonlinear crystal for generating the fundamental wave and the fourth-order harmonic wave, and a fifth-order harmonic wave generation nonlinear crystal for generating the fundamental wave and the fifth-order harmonic wave, and
wherein the final emission units comprise:
a first ultraviolet filter, disposed between the fourth-order harmonic wave generation nonlinear crystal and the fifth-order harmonic wave generation nonlinear crystal, for reflecting the second-order harmonic wave and transmitting the fundamental wave and the fourth-order harmonic wave;
a 2-1-th ultraviolet filter, disposed behind the fifth-order harmonic wave generation nonlinear crystal, for transmitting the fundamental wave and the fourth-order harmonic wave and reflecting the fifth-order harmonic wave; and
a 2-2-th ultraviolet filter for reflecting and thereby emitting the fifth-order harmonic wave, reflected from the 2-1-th ultraviolet filter.

2. The high-order harmonic wave generation apparatus of claim 1 , wherein the emitted harmonic wave has an output wavelength that is equal to or less than 300 nm.

3. The high-order harmonic wave generation apparatus of claim 1 , wherein the pump head comprises a laser diode array and a gain medium.

4. The high-order harmonic wave generation apparatus of claim 1 , wherein the nonlinear crystals are any one of Beta-Barium Borate, Deuterated Potassium Dihydrogen, and Cesium Lithium Borate.

5. The high-order harmonic wave generation apparatus of claim 1 , wherein each of the nonlinear crystals is implemented along with a Thermoelectric Cooler (TEC) in order to maintain a phase-matching temperature.

6. The high-order harmonic wave generation apparatus of claim 1 , wherein
the final emission units select either the fourth-order harmonic wave or the fifth-order harmonic wave when emitting the harmonic wave.

7. A high-order harmonic wave generation apparatus for selecting a wavelength, comprising:
Porro prisms, arranged on a left side and a right side of a pump head in order to make a fundamental wave, generated by the pump head, insensitive to a change in an external environment;
nonlinear crystals for sequentially generating a second-order harmonic wave, a fourth-order harmonic wave, and a fifth-order harmonic wave from the fundamental wave; and
final emission units for reflecting and transmitting the second-order harmonic wave, the fourth-order harmonic wave, and the fifth-order harmonic wave and for emitting the harmonic wave without changing an optical path,
wherein the nonlinear crystals comprise a second-order harmonic wave generation nonlinear crystal for generating the fundamental wave and the second-order harmonic wave, a fourth-order harmonic wave generation nonlinear crystal for generating the fundamental wave and the fourth-order harmonic wave, and a fifth-order harmonic wave generation nonlinear crystal for generating the fundamental wave and the fifth-order harmonic wave,
wherein the final emission units select either the fourth-order harmonic wave or the fifth-order harmonic wave when emitting the harmonic wave, and
wherein the final emission units comprise:
a first ultraviolet filter, disposed between the fourth-order harmonic wave generation nonlinear crystal and the fifth-order harmonic wave generation nonlinear crystal, for reflecting the second-order harmonic wave and transmitting the fundamental wave and the fourth-order harmonic wave;
a 2-1-th ultraviolet filter, disposed behind the fifth-order harmonic wave generation nonlinear crystal, for transmitting the fundamental wave and the fourth-order harmonic wave and reflecting the fifth-order harmonic wave;
a 2-2-th ultraviolet filter for reflecting and thereby emitting the fifth-order harmonic wave, reflected from the 2-1-th ultraviolet filter; and
a wavelength selection substrate for selecting either the fourth-order harmonic wave or the fifth-order harmonic wave to be emitted, depending on a selection of the 2-1 th ultraviolet filter and the 2-2-th ultraviolet filter.

8. The high-order harmonic wave generation apparatus of claim 7 , wherein the wavelength selection substrate comprises:
a third ultraviolet filter, disposed to face the 2-1-th ultraviolet filter in a horizontal direction, for transmitting the fundamental wave and reflecting the fourth-order harmonic wave; and
a fourth ultraviolet filter that is disposed to face the 2-2-th ultraviolet filter in a horizontal direction so as to reflect the fifth-order harmonic wave and simultaneously to face the third ultraviolet filter in a vertical direction so as to reflect and thereby emit the fourth-order harmonic wave,
wherein when the third ultraviolet filter does not face the 2-1-th ultraviolet filter and, simultaneously, the fourth ultraviolet filter does not face the 2-2-th ultraviolet filter, the fourth-order harmonic wave is emitted.

Assignees

• Agency Defense Dev

Inventors

• Ha Yeon-Chul
• Lee Jae-Hwan
• Kang Young-Il
• Cho Ki-Ho
• Kim Jae-Ihn
• Cho Joon-Young

Classifications

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• H01S3/109 Primary

  Frequency multiplication, e.g. harmonic generation · CPC title

• H01S3/0941

  of a laser diode · CPC title

• H01S3/0405

  Conductive cooling, e.g. by heat sinks or thermo-electric elements · CPC title

• H01S3/0401

  of optical elements being part of laser resonator, e.g. windows, mirrors, lenses · CPC title