# US 10,768,049 B2 · High-resolution terahertz wave concentration module, scattered light detection module, and high-resolution inspection apparatus using terahertz Bessel beam > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,049 B2 - Document ID: US10768049B2 - Status: Granted - Kind: B2 - Application number: 16/800,077 - Filed: 2020-02-25 - Published: 2020-06-18 - Granted: 2020-09-08 - Earliest claimed: 2016-11-01 - Assignees: Korea Research Institute - Applicants: Korea Food Research Institute - Inventors: Gyeong-Sik Ok; Sung-Wook Choi; Hyun-Joo Chang - Web page: https://patentgrep.com/patent/US10768049B2 ## CPC - G01J 3/42: Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry (beam switching arrangements G01J3/08) - G01J 3/0208: {using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction} - G01N 21/3581: using far infrared light; using Terahertz radiation - G01N 21/85: Investigating moving fluids or granular solids - G01N 21/8806: {Specially adapted optical and illumination features} - G01V 8/10: Detecting, e.g. by using light barriers (by reflection from the object G01S17/00) - G01V 8/14: using reflectors - G01V 8/18: using mechanical scanning systems - G02B 5/00: Optical elements other than lenses (light guides G02B6/00; optical logic elements G02F3/00) - G02B 5/001: {Axicons, waxicons, reflaxicons} - G02B 27/0927: {Systems for changing the beam intensity distribution, e.g. Gaussian to top-hat} - G02B 27/095: {Refractive optical elements} - G01J 2003/425: {Reflectance} - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## 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 forming a terahertz Bessel beam at an inspection target object using a terahertz wave incident from the terahertz wave generating unit; a first lens for changing an angle of the terahertz wave radiated, when the terahertz Bessel beam is transmitted through the inspection target object, to be smaller; a second lens for concentrating the terahertz wave passing through the first lens and toward a detection unit; and a terahertz wave detection unit for detecting the terahertz wave concentrated by the second lens. ## Claims ### Claim 1 A high resolution inspection apparatus using a terahertz Bessel beam, the high resolution inspection apparatus comprising: a terahertz wave generating unit generating a terahertz wave; a Bessel beam forming unit forming a terahertz Bessel beam at an inspection target object using a terahertz wave incident from the terahertz wave generating unit; a first lens changing an angle of the terahertz wave radiated, when the terahertz Bessel beam is transmitted through the inspection target object, to be smaller; a second lens concentrating the terahertz wave passing through the first lens and toward a terahertz wave detection unit; the terahertz wave detection unit for detecting the terahertz wave concentrated by the second lens; and the Bessel beam forming unit is a first axicon lens having an apical angle at which a diameter of the terahertz Bessel beam is smaller than a wavelength of the terahertz wave generated by the terahertz wave generating unit. ### Claim 2 (depends on 1) The high resolution inspection apparatus of claim 1, wherein a minimum value of the first axicon lens has an apical angle of the first axicon lens at which total internal reflection, according to the refractive index of the first axicon, does not occur. ### Claim 3 (depends on 1) The high resolution inspection apparatus of claim 1, wherein the first lens is a second axicon lens arranged to be symmetrical to the first axicon lens with respect to the inspection target object. ### Claim 4 (depends on 2) The high resolution inspection apparatus of claim 2, wherein the second axicon lens has an apical angle which has a same size as the first axicon lens. ### Claim 5 (depends on 1) The high resolution inspection apparatus of claim 1, further include angle changing unit for changing an angle of the terahertz wave incident from the terahertz wave generating unit to be smaller and to enter the Bessel beam forming unit. ### Claim 6 (depends on 4) The high resolution inspection apparatus of claim 4, wherein the angle changing unit is a first convex lens for changing the angle of the terahertz wave incident from the terahertz wave generating unit to be smaller; and the second lens is a second convex lens arranged to be symmetrical to the first convex lens with respect to the inspection target object. ### Claim 7 (depends on 2) The high resolution inspection apparatus of claim 2, wherein the second lens is a third axicon lens having a same shape as the second axicon lens and arranged to be symmetrical to the second axicon lens with respect to an axis perpendicular to an optical axis. ### Claim 8 (depends on 2) The high resolution inspection apparatus of claim 2, wherein the first lens is a third convex lens for changing an angle of the terahertz wave radiated when the terahertz Bessel beam is transmitted through the inspection target object. ### Claim 9 (depends on 7) The high resolution inspection apparatus of claim 7, wherein the second lens is a fourth convex lens arranged to be symmetrical to the third convex lens with respect to the axis perpendicular to the optical axis.