High-resolution terahertz wave concentration module, scattered light detection module, and high-resolution inspection apparatus using terahertz bessel beam

Patent metadata

Field	Value
Publication number	US-11248960-B2
Application number	US-202017137881-A
Country	US
Kind code	B2
Filing date	Dec 30, 2020
Priority date	Nov 1, 2016
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A high resolution inspection apparatus using a terahertz Bessel beam. The high resolution inspection apparatus comprises a terahertz wave generating unit for generating a terahertz wave; a Bessel beam forming unit for generating a terahertz Bessel beam using the terahertz wave incident from the terahertz wave generating unit; a ring beam forming unit for forming a ring beam using the terahertz Bessel beam and concentrating the formed ring beam to an inspection target object; a scattered light detecting unit for detecting scattered light generated from the inspection target object; and a ring beam detecting unit for detecting a ring beam transmitted through the inspection target object.

First claim

The invention claimed is:

1. A high resolution inspection apparatus using a terahertz Bessel beam, the high resolution inspection apparatus comprising:
a terahertz wave generating unit for generating a terahertz wave;
a Bessel beam forming unit for generating a terahertz Bessel beam using the terahertz wave incident from the terahertz wave generating unit;
a ring beam forming unit for forming a ring beam using the terahertz Bessel beam and concentrating the formed ring beam to an inspection target object;
a scattered light detecting unit for detecting scattered light generated from the inspection target object; and
a ring beam detecting unit for detecting a ring beam transmitted through the inspection target object.

2. The high resolution inspection apparatus of claim 1 , wherein the ring beam forming unit includes a first lens for forming a ring beam and concentrating the formed ring beam to the inspection target object.

3. The high resolution inspection apparatus of claim 2 , the scattered light detecting unit includes a reflected scattered light detecting unit provided inside the ring beam exiting from the first lens and detecting scattered light reflected from the inspection target object.

4. The high resolution inspection apparatus of claim 2 ,
the scattered light detecting unit includes a transmitted scattered light detecting unit arranged inside a ring beam incident from the first lens and detecting scattered light transmitted from the inspection target object.

5. A high resolution inspection apparatus using a terahertz Bessel beam, the high resolution inspection apparatus comprising:
a scanner scanning a shape of an inspection target object;
a terahertz wave optical head for generating a terahertz wave and irradiating the inspection target object with the generated terahertz wave;
a terahertz wave concentrating head for detecting the terahertz wave transmitted through the inspection target object;
a first transfer unit for moving the terahertz wave optical head according to the scanned shape of the inspection target object; and
a second transfer unit for moving the terahertz wave concentrating head in a same manner as the optical head in synchronization with the first transfer unit,
the terahertz wave optical head includes:
a terahertz wave generating unit for generating a terahertz wave;
a Bessel beam forming unit for forming a terahertz Bessel beam using the terahertz wave incident from the terahertz wave generating unit; and
a ring beam forming unit for forming a ring beam using the terahertz Bessel beam and concentrating the formed ring beam to an inspection target object; and

the terahertz wave concentrating head includes:
a scattered light detecting unit for detecting scattered light generated from the inspection target object; and
a ring beam detecting unit for detecting a ring beam transmitted through the inspection target object.

6. The high resolution inspection apparatus of claim 5 , wherein the first transfer unit moves the terahertz wave optical head to maintain a predetermined distance to the inspection target object on a basis of a thickness of the scanned inspection target object so that the inspection target object is placed within a depth of focus of the generated terahertz wave.

7. The high resolution inspection apparatus of claim 5 , further including a rapid cooling device for maintaining the inspection target object in a low temperature state, wherein the terahertz wave optical head and the terahertz wave concentrating head are disposed on opposing sides of the rapid cooling device so as to be spaced apart from each other.

8. The high resolution inspection apparatus of claim 7 , wherein the rapid cooling device is configured as a housing including a window which allows the generated terahertz wave to be transmitted therethrough.

9. The high resolution inspection apparatus of claim 7 , further including a defrosting device disposed in a rear stage of the rapid cooling device and defrosting the inspection target object.

Assignees

• Korea Food Res Inst

Inventors

• Ok Gyeong-Sik
• Choi Sung-Wook
• Chang Hyun-Joo

Classifications

• G02B5/00

  Optical elements other than lenses (light guides G02B6/00; optical logic elements G02F3/00) · CPC title

• G01J3/0208

  using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction · CPC title

• G01V8/18

  using mechanical scanning systems · CPC title

• G02B27/0927

  Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat · CPC title

• G01J2003/425

  Reflectance · CPC title