Terahertz wave generator

Patent metadata

Field	Value
Publication number	US-10241380-B2
Application number	US-201715801869-A
Country	US
Kind code	B2
Filing date	Nov 2, 2017
Priority date	Nov 11, 2016
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A terahertz wave generator 1 includes a nonlinear crystal 4, which is capable of generating a terahertz wave TH, a pumping beam emitter 2, which emits a pumping beam L1, a seed beam emitter 3, which is disposed so as to be parallel to a nonlinear crystal 4 and emits a seed beam L2, a first total reflection mirror 17 and a second total reflection mirror 18, which successively reflect the seed beam L2 emitted from the seed beam emitter 3 to cause the seed beam L2 to be incident on the nonlinear crystal 4, and a convex lens 6, which collects the seed beam L2.

First claim

What is claimed is:

1. A terahertz wave generator comprising a nonlinear crystal capable of generating a terahertz wave based on a parametric effect, a pumping beam emitter that emits a pumping beam, a seed beam emitter capable of changing a wavelength of an emitted seed beam, beam guide means for guiding the seed beam emitted from the seed beam emitter to the nonlinear crystal and including a first mirror that reflects the seed beam emitted from the seed beam emitter at a first angle of reflection, a convex lens that is disposed perpendicularly to an optical path of the seed beam reflected by the first mirror and collects the seed beam, a movable stage that is configured to be movable along the optical path of the seed beam incident on the first mirror and supporting the first mirror at a predetermined angle with respect to the optical path of the seed beam, and a movement mechanism for moving a reflection surface of the first mirror along the optical path of the seed beam incident on the first mirror by moving the movable stage, wherein the terahertz wave generator is configured so that the pumping beam and the seed beam are caused to be incident on the nonlinear crystal at an angle of incidence that satisfies a phase matching condition to cause the nonlinear crystal to generate the terahertz wave and the first mirror is simply moved by the movement mechanism in accordance with the wavelength of the seed beam emitted from the seed beam emitter to change a position where the seed beam is incident on the convex lens so that the angle of incidence of the seed beam incident on the nonlinear crystal is changed to satisfy the phase matching condition.

2. The terahertz wave generator according to claim 1 , characterized in that the pumping beam emitter and the seed beam emitter are disposed so that the pumping beam emitted from the pumping beam emitter and the seed beam between the seed beam emitter and the first mirror are parallel to each other and a stationary second mirror that reflects the seed beam reflected off the first mirror towards the nonlinear crystal is provided.

3. A terahertz wave generator comprising a nonlinear crystal capable of generating a terahertz wave based on a parametric effect, a pumping beam emitter that emits a pumping beam, a seed beam emitter capable of changing a wavelength of an emitted seed beam, beam guide means for guiding the seed beam emitted from the seed beam emitter to the nonlinear crystal and including a first mirror that reflects the seed beam emitted from the seed beam emitter at a first angle of reflection, a convex lens that is disposed perpendicularly to an optical path of the seed beam reflected by the first mirror and collects the seed beam, a movable stage that is configured to be movable along the optical path of the seed beam incident on the first mirror and supporting the first mirror at a predetermined angle with respect to the optical path of the seed beam, and a movement mechanism for moving a reflection surface of the first mirror along the optical path of the seed beam incident on the first mirror by moving the movable stage, wherein the terahertz wave generator is configured so that the pumping beam and the seed beam are caused to be incident on the nonlinear crystal at an angle of incidence that satisfies a phase matching condition to cause the nonlinear crystal to generate the terahertz wave, the first mirror is simply moved by the movement mechanism in accordance with the wavelength of the seed beam emitted from the seed beam emitter to change a position where the seed beam is incident on the convex lens so that the angle of incidence of the seed beam incident on the nonlinear crystal is changed to satisfy the phase matching condition, the pumping beam emitter and the seed beam emitter are disposed so that the pumping beam emitted from the pumping beam emitter and the seed beam between the seed beam emitter and the first mirror are parallel to each other and a stationary second mirror that reflects the seed beam reflected off the first mirror towards the nonlinear crystal is provided.

Assignees

• Shibuya Corp

Inventors

• Naka Toshiaki
• Sasaki Motoi
• Tsuchiya Akito

Classifications

• G02F2203/13

  involving THZ radiation · CPC title

• G02F1/3544

  Particular phase matching techniques · CPC title

• G02F1/3534

  Three-wave interaction, e.g. sum-difference frequency generation (G02F1/3532 takes precedence) · CPC title

• G02F1/39 Primary

  for parametric generation or amplification of light, infrared or ultraviolet waves · CPC title

• G02F1/3501

  Constructional details or arrangements of non-linear optical devices, e.g. shape of non-linear crystals · CPC title