# US 12,184,030 B2 · Broadband light source device and method of creating broadband light pulses > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,030 B2 - Document ID: US12184030B2 - Status: Granted - Kind: B2 - Application number: 18/133,597 - Filed: 2023-04-12 - Published: 2023-08-24 - Granted: 2024-12-31 - Earliest claimed: 2020-05-15 - Assignees: Max-Planck-Gesellschaft Zur FöRderung Der Wissenschaften E. V. - Applicants: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. - Inventors: Patrick Sebastian Uebel; Philip St. J. Russell; Sebastian Thomas Bauerschmidt - Web page: https://patentgrep.com/patent/US12184030B2 ## CPC - H01S 3/0092: {Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35)} - G02B 6/02328: {Hollow or gas filled core} - G02B 6/02357: {Property of longitudinal structures or background material varies radially and/or azimuthally in the cladding, e.g. size, spacing, periodicity, shape, refractive index, graded index, quasiperiodic, quasicrystals} - G02F 1/3501: {Constructional details or arrangements of non-linear optical devices, e.g. shape of non-linear crystals} - G02F 1/353: {Frequency conversion, i.e. wherein a light beam is generated with frequency components different from those of the incident light beams} - G02F 1/355: characterised by the materials used - G02F 1/365: in an optical waveguide structure (G02F1/377, {G02F1/395} take precedence) - G02F 1/3528: {for producing a supercontinuum} - H01S 3/0407: {Liquid cooling, e.g. by water} - H01S 3/1305: {Feedback control systems} - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A broadband light source device for creating broadband light pulses includes a hollow-core fiber and a pump laser source device. The hollow-core fiber is configured to create the broadband light pulses by an optical non-linear broadening of pump laser pulses. The hollow-core fiber includes a filling gas, an axial hollow light guiding fiber core configured to support core modes of a guided light field, and an inner fiber structure surrounding the fiber core and configured to support transverse wall modes of the guided light field. The pump laser source device is configured to create and provide the pump laser pulses at an input side of the hollow-core fiber. The transverse wall modes include a fundamental transverse wall mode and second and higher order transverse wall modes. ## Claims ### Claim 1 A broadband light source comprising: a gas cell comprising a filling gas and an input window configured to receive pump laser pulses; and a hollow-core photonic crystal fiber of non-bandgap type at least partially enclosed within the gas cell and configured to create broadband light pulses, the hollow-core photonic crystal fiber comprising: a hollow core configured to support core modes of a guided light field; and a ring of capillaries surrounding the hollow core and configured to support transverse wall modes of the guided light field, wherein a wall thickness of the ring of capillaries is in a range from 70 nm to 150 nm. ### Claim 2 (depends on 1) The broadband light source of claim 1, wherein the wall thickness being in the range from 70 nm to 150 nm is configured to suppress resonances of the core modes and transverse wall modes. ### Claim 3 (depends on 1) The broadband light source of claim 1, wherein the wall thickness is in the range from 70 nm to 150 nm thereby providing a spectral separation from all transverse wall modes. ### Claim 4 (depends on 1) The broadband light source of claim 1, wherein the wall thickness is no greater than 120 nm thereby reducing a number of resonances in a transmission spectrum of the broadband light source. ### Claim 5 (depends on 1) The broadband light source of claim 1, wherein the wall thickness (t) is such that t < λ min 2 ⁢ n 2 2 - n 1 2 wherein λmin is a shortest wavelength of a core mode spectrum, n1 is a refractive index of the filling gas in the hollow-core photonic crystal fiber, and n2 is a refractive index of the ring of capillaries. ### Claim 6 (depends on 1) The broadband light source of claim 1, wherein the wall thickness is such that at least second and higher order transverse wall modes are spectrally shifted to shorter wavelengths relative to a core mode spectrum. ### Claim 7 (depends on 6) The broadband light source of claim 6, wherein the wall thickness is such that all transverse wall modes are spectrally shifted to shorter wavelengths relative to the core mode spectrum. ### Claim 8 (depends on 1) The broadband light source of claim 1, wherein the wall thickness varies along a length of the hollow-core photonic crystal fiber. ### Claim 9 (depends on 8) The broadband light source of claim 8, wherein the wall thickness at an input side of the hollow-core photonic crystal fiber is greater than the wall thickness at an output side of the hollow-core photonic crystal fiber. ### Claim 10 (depends on 8) The broadband light source of claim 8, wherein: a longitudinal section of the hollow-core photonic crystal fiber exclusively has the wall thickness; and the broadband light pulses are created and transmitted through the hollow-core photonic crystal fiber. ### Claim 11 (depends on 1) The broadband light source of claim 1, wherein capillaries of the ring of capillaries are arranged symmetrically about the hollow core. ### Claim 12 (depends on 1) The broadband light source of claim 1, wherein the wall thickness being in the range from 70 nm to 150 nm is configured to increase a lifetime of the hollow-core photonic crystal fiber. ### Claim 13 (depends on 12) The broadband light source of claim 12, wherein the lifetime of the hollow-core photonic crystal fiber is increased by at least a factor of 300 relative to a conventional hollow fiber. ### Claim 14 A method of creating broadband light pulses, the method comprising: coupling pump laser pulses into a hollow-core photonic crystal fiber of non-bandgap type including a filling gas, wherein the hollow-core photonic crystal fiber comprises: a hollow core configured to support core modes of a guided light field; and a ring of capillaries surrounding the hollow core and configured to support transverse wall modes of the guided light field; and creating broadband light pulses by an optical non-linear broadening of the pump laser pulses in the hollow-core photonic crystal fiber, wherein a wall thickness of the ring of capillaries is in a range from 70 nm to 150 nm. ### Claim 15 (depends on 14) The method of claim 14, wherein the ring of capillaries comprises a single ring. ### Claim 16 A broadband light source comprising: a gas cell comprising a filling gas and an input window configured to receive pump laser pulses; and a hollow-core photonic crystal fiber of non-bandgap type at least partially enclosed within the gas cell and configured to create broadband light pulses, the hollow-core photonic crystal fiber comprising: a hollow core configured to support core modes of a guided light field; and a ring of capillaries surrounding the hollow core and configured to support transverse wall modes of the guided light field, wherein a wall thickness (t) of the ring of capillaries is such that t < λ min 2 ⁢ n 2 2 - n 1 2 wherein λmin is a shortest wavelength of a core mode spectrum, n1 is a refractive index of the filling gas in the hollow-core photonic crystal fiber, and n2 is a refractive index of the ring of capillaries. ### Claim 17 (depends on 16) The broadband light source of claim 16, wherein the wall thickness is in a range from 70 nm to 150 nm. ### Claim 18 (depends on 16) The broadband light source of claim 16, wherein the shortest wavelength λmin of the core mode spectrum is in a range from 170 nm to 250 nm. ### Claim 19 (depends on 16) The broadband light source of claim 16, wherein the wall thickness varies along a length of the hollow-core photonic crystal fiber. ### Claim 20 (depends on 16) The broadband light source of claim 16, wherein the ring of capillaries comprises a single ring.