# US 11,307,096 B2 · Spectral resolution enhancement device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,307,096 B2 - Document ID: US11307096B2 - Status: Granted - Kind: B2 - Application number: 17/351,164 - Filed: 2021-06-17 - Published: 2021-10-14 - Granted: 2022-04-19 - Earliest claimed: 2019-09-17 - Assignees: Huazhong University of Science and Technology - Applicants: Huazhong University of Science and Technology - Inventors: Chen Liu - Web page: https://patentgrep.com/patent/US11307096B2 ## CPC - G01J 3/2823: {Imaging spectrometer} - G01J 3/0208: {using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction} - G01J 3/18: using diffraction elements, e.g. grating (gratings per se G02B) - G02B 5/1842: {Gratings for image generation (G02B5/1847 takes precedence)} - G02B 27/4272: {having plural diffractive elements positioned sequentially along the optical path} - G01J 2003/1842: {Types of grating} - G02B 5/1861: {Reflection gratings characterised by their structure, e.g. step profile, contours of substrate or grooves, pitch variations, materials (G02B5/1809, G02B5/1828, G02B5/1833, G02B5/1838 and G02B5/1847 take precedence)} - 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) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A spectral resolution enhancement device including a preliminary dispersion unit, a two-grating angular dispersion amplification unit, and a detection unit is provided. The preliminary dispersion unit is configured to receive collimated incident light and emits light of different wavelengths in the incident light at different angles. The two-grating angular dispersion amplification unit is configured to diffract the light of different wavelengths and emitted from the preliminary dispersion unit multiple times, such that angular dispersion the light of different wavelengths is enhanced, and emergent angle deviations between the light of different wavelengths are increased. The detection unit is configured to detect light of different wavelengths and emitted from the two-grating angular dispersion amplification unit. Since the emergent angle deviations of light of different wavelengths are increased, resolution of the detection unit for the light of different wavelengths is increased. ## Claims ### Claim 1 A spectral resolution enhancement device, comprising: a preliminary dispersion unit, a two-grating angular dispersion amplification unit, and a detection unit, wherein the preliminary dispersion unit is configured to receive collimated incident light and emits light of different wavelengths in the incident light at different angles, the two-grating angular dispersion amplification unit is configured to diffract the light of different wavelengths emitted from the preliminary dispersion unit at least three times, such that angular dispersions of the light of different wavelengths is enhanced, and emergent angle deviations of the light of different wavelengths are increased, the detection unit is configured to detect the light of different wavelengths emitted from the two-grating angular dispersion amplification unit, and since the emergent angle deviations of the light of different wavelengths are increased, resolution of the detection unit for the light of different wavelengths is increased, the two-grating angular dispersion amplification unit comprises a first blazed grating and a second blazed grating, the first blazed grating receives the light emitted from the preliminary dispersion unit with different wavelengths and diffracts the light with different wavelengths to the second blazed grating, the second blazed grating receives the light diffracted from the first blazed grating with different wavelengths and diffracts the light with different wavelengths to the first blazed grating, and the foregoing is repeated, finally, diffracted light with different wavelengths is emitted to the detection unit after being diffracted by the first blazed grating or the second blazed grating, when the diffracted light with different wavelengths is emitted to the detection unit after being diffracted by the first blazed grating, an incident angle of the light is changed from being greater than a Littrow angle to being less than the Littrow angle when the light is diffracted multiple times between the first blazed grating and the second blazed grating through arrangement of positions of the first blazed grating and the second blazed grating, the detection unit includes: a beam splitter, an imaging lens, and a detector, the imaging lens is configured to focus the emitted light with different wavelengths on the detector, the detector is configured to detect the light with different wavelengths and emitted from the two-grating angular dispersion amplification unit. ### Claim 2 (depends on 1) The spectral resolution enhancement device according to claim 1, wherein the preliminary dispersion unit comprises: an incident slit, a collimating lens, and a diffraction grating, the incident light is incident through the incident slit, the collimating lens is configured to collimate the incident light passing through the incident slit and emits the incident light in parallel, the diffraction grating is configured to receive the incident light emitted from the collimating lens and emit the light of different wavelengths in the incident light at different angles. ### Claim 3 (depends on 1) The spectral resolution enhancement device according to claim 1, wherein by arranging the positions of the first blazed grating and the second blazed grating, the incident angle of the light is changed from being greater than the Littrow angle to being less than the Littrow angle when the light is diffracted multiple times between the first blazed grating and the second blazed grating, and when the incident angle reaches the Littrow angle after being diffracted multiple times, a diffraction angle is identical to the incident angle, and a light beam is emitted to the beam splitter after being diffracted multiple times in a reverse direction alone an original diffraction path. ### Claim 4 (depends on 1) The spectral resolution enhancement device according to claim 1, wherein an angular dispersion of jth grating diffraction is Dj, and a recurrence relationship is: D j = cos ⁢ ⁢ ( i j ) cos ⁢ ⁢ ( θ j ) ⁢ D j - 1 + m d ⁢ cos ⁢ ⁢ ( θ j ) wherein Dj-1 is an angular dispersion of j−1th grating diffraction, ij is an incident angle of jth diffraction, θj is a diffraction angle of the jth diffraction, m is a diffraction order of a blazed grating, and d is a grating constant. ### Claim 5 (depends on 1) The spectral resolution enhancement device according to claim 1, wherein if the diffracted light with different wavelengths is emitted to the detection unit after being diffracted by the first blazed grating, a width of an incident light beam received by the detection unit does not change, a size of an imaging speckle does not change, and an angular dispersion multiple of the light with different wavelengths is a spectral resolution enhancement multiple through the device, if the diffracted light having different wavelengths is emitted to the detection unit after being diffracted by the second blazed grating, the incident light beam received by the detection unit is reduced, a divergence angle of the reduced light beam is expanded, angular spectrum distribution is increased, the imaging speckle is increased, and spectral resolution of the device is a full width at half maximum of a detected speckle. ### Claim 6 (depends on 2) The spectral resolution enhancement device according to claim 2, wherein an angular dispersion of jth grating diffraction is Dj, and a recurrence relationship is: D j = cos ⁢ ⁢ ( i j ) cos ⁢ ⁢ ( θ j ) ⁢ D j - 1 + m d ⁢ cos ⁢ ⁢ ( θ j ) wherein Dj-1 is an angular dispersion of j−1th grating diffraction, ij is an incident angle of jth diffraction, θj is a diffraction angle of the jth diffraction, m is a diffraction order of a blazed grating, and d is a grating constant. ### Claim 7 (depends on 3) The spectral resolution enhancement device according to claim 3, wherein an angular dispersion of jth grating diffraction is Dj, and a recurrence relationship is: D j = cos ⁢ ⁢ ( i j ) cos ⁢ ⁢ ( θ j ) ⁢ D j - 1 + m d ⁢ cos ⁢ ⁢ ( θ j ) wherein Dj-1 is an angular dispersion of j−1th grating diffraction, ij an incident angle of jth diffraction, θj is a diffraction angle of the jth diffraction, m is a diffraction order of a blazed grating, and d is a grating constant.