Electro-optic terahertz detector

Patent metadata

Field	Value
Publication number	US-10203248-B2
Application number	US-201615562529-A
Country	US
Kind code	B2
Filing date	Mar 29, 2016
Priority date	Mar 30, 2015
Publication date	Feb 12, 2019
Grant date	Feb 12, 2019

Abstract

An electro-optic detector for detecting terahertz radiation comprising an electro-optic material through which the terahertz radiation passes; a probe for transmitting probe radiation into the electro-optic material; an optical arrangement for causing the probe radiation to make multiple passes through the electro-optic material and a radiation detector for detecting the probe radiation after the multiple passes are made.

First claim

The invention claimed is:

1. An electro-optic detector for detecting terahertz radiation comprising:
an electro-optic material through which the terahertz radiation passes;
a source of probe radiation for illuminating the electro-optic material;
an optical arrangement for causing the probe radiation to make multiple passes through the electro-optic material;
a combination of polarizing and analyzing optics; and
a radiation detector for detecting the probe radiation after the multiple passes are made,
wherein the polarizing optics are configured to determine the input polarization state, and the analyzing optics and the radiation detector are together configured to monitor the output polarization state of the probe radiation after the multiple passes through the electro-optic material are made, and
wherein the optical arrangement is such that each time that any particular wavefront of the probe radiation passes through the electro-optic material in the same direction as the terahertz radiation, this wavefront meets the terahertz radiation at the same point in the phase cycle of the terahertz wave as it did on its previous transit.

2. A detector as claimed in claim 1 , wherein the optical arrangement comprises two mirrors.

3. A detector as claimed in claim 2 , wherein the two mirrors are parallel.

4. A detector as claimed in claim 1 , wherein the optical arrangement is such that the multiple passes of the probe radiation are brought about by zig-zagging the probe radiation through the electro-optic material.

5. A detector as claimed in claim 4 , wherein the zig-zagging is arranged to fill a cross-sectional area within the electro-optic crystal that matches the cross-sectional area associated with the terahertz radiation being detected.

6. A detector as claimed in claim 2 , wherein the probe radiation is resonant in a cavity formed between the mirrors.

7. A detector as claimed in claim 6 , wherein the mirrors define a Fabry-Perot type interferometer.

8. An electro-optic detector for detecting terahertz radiation comprising:
an electro-optic material through which the terahertz radiation passes;
a probe for transmitting probe radiation into the electro-optic material;
an optical arrangement for causing the probe radiation to make multiple passes through the electro-optic material; and
a radiation detector for detecting the probe radiation after the multiple passes through the electro-optic material are made,
wherein the optical arrangement is such that the multiple passes of the probe radiation are brought about by zig-zagging the probe radiation through the electro-optic material.

9. A detector as claimed in claim 8 , wherein the zig-zagging is arranged to fill a cross-sectional area within the electro-optic crystal that matches the cross-sectional area associated with the terahertz radiation being detected.

Assignees

• Univ Court Univ St Andrews

Inventors

• Dunn Malcolm Harry

Classifications

• G02B5/08

  Mirrors {(vehicle mirrors involving special optical features B60R1/08)} · CPC title

• G01J3/0224

  using polarising or depolarising elements · CPC title

• G01J1/4257

  applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam (monitoring arrangements for lasers in general H01S3/0014) · CPC title

• G01J2003/425

  Reflectance · CPC title

• G01J1/0429

  using polarisation elements · CPC title