# US 2014/0153597 A1 · Apparatus for generating short-pulse laser using temporally modulated sideband gain > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153597 A1 - Document ID: US20140153597A1 - Status: Published application - Kind: A1 - Application number: 13/903,857 - Filed: 2013-05-28 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: Industrial Technology Research Institute - Applicants: Industrial Technology Research Institute - Inventors: Yao-Wun JHANG; Chien-Ming Huang; Hsin-Chia Su; Shih-Ting Lin; Chih-Lin Wang; Hong-Xi Tsau - Web page: https://patentgrep.com/patent/US20140153597A1 ## CPC - H01S 5/0057: {for temporal shaping, e.g. pulse compression, frequency chirping} - H01S 5/06216: {Pulse modulation or generation} - H01S 5/0656: {Seeding, i.e. an additional light input is provided for controlling the laser modes, for example by back-reflecting light from an external optical component (H01S5/14, H01S5/4062 and H01S5/4006 take precedence)} - H01S 5/0014: {Measuring characteristics or properties thereof (measuring techniques per se G01J, G01K, G01N, G01R)} - H01S 5/146: {using a fiber as external cavity} - 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 ## Abstract An apparatus for generating a short-pulse laser using a temporally modulated sideband gain is provided. The apparatus includes a laser diode and an external reflector. By use of a time difference resulted by a nanosecond laser pulse signal at the external reflector, a sideband gain is obtained for generating a short-pulse picosecond laser output. ## Claims ### Claim 1 An apparatus for generating a short-pulse laser using a temporally modulated sideband gain, comprising: at least one pulse driver modulator; a laser diode, having one end connected to the pulse driver modulator, and having a nanosecond pulse repetition rate and a pulse width of a programmable semiconductor optical output; an external reflector, having one input end connected to one output end of the laser diode; and a wavelength filter, having one end connected to one output end of the external reflector, for blocking a long-pulse laser signal having a first wavelength pulse, and outputting a single short-pulse laser signal having a second wavelength pulse at one end thereof. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein: at a first time point, the laser diode outputs the first wavelength pulse; when entering a second time point from the first time point, the first wavelength pulse passes the external reflector, a sideband of the first wavelength pulse is reflected via the external reflector to the laser diode to form the second wavelength pulse, and the external reflector removes the first wavelength pulse; when entering a third time point from the second time point, the second wavelength pulse falls within a retrieval period in which the laser diode is turned off to form the second wavelength picosecond short pulse, and laser signal strength of the second wavelength picosecond short pulse is amplified via the laser diode; when entering a fourth time point from the third time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted to the external reflector; when entering a fifth time point from the fourth time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted via the external reflector to the wavelength filter; and when entering a sixth time point from the fifth time point, the wavelength filter removes the laser signal having the first wavelength pulse, and outputs the single short-pulse laser signal having the second wavelength picosecond short pulse. ### Claim 3 (depends on 2) The apparatus according to claim 2, wherein the laser adjusts a wavelength of a main wavelength in the first wavelength pulse through temperature control to correspondingly adjust a wavelength of the first wavelength pulse, and the main wavelength in the first wavelength pulse is a nanosecond optical source. ### Claim 4 (depends on 3) The apparatus according to claim 3, wherein the pulse driver modulator provides a modulation range of between 1 and 1,000,000 times/second (Hz), and a pulse width range of between 1 ns and 100 μs. ### Claim 5 (depends on 4) The apparatus according to claim 4, wherein the pulse driver modulator for generating the laser signal having the main wavelength in the first wavelength in nanoseconds outputs a wavelength range of between 800 nm and 1600 nm. ### Claim 6 An apparatus for generating a short-pulse laser using a temporally modulated sideband gain, comprising: at least one pulse driver modulator; a laser diode, having one end connected to the pulse driver modulator, and having a nanosecond pulse repetition rate and a pulse width of a programmable semiconductor optical output; an external reflector, having one input end connected to one output end of the laser diode; and a wavelength filter, having one end connected to one output end of the external reflector, for blocking a long-pulse laser signal having a first wavelength pulse, and outputting a single short-pulse laser signal having a second wavelength pulse at one end thereof; wherein, the external reflector comprises: an extension optical fiber, having one end connected to one end of the laser diode; an optical fiber coupler, having one end connected to one end of the extension optical fiber, and one other end connected to one end of the external reflector; a reflection coupler, having one end connected to one input end of a loop optical fiber, and one other end connected to one output end of the loop optical fiber; and a sideband filter, having one input end connected to the loop optical fiber, for inputting the laser signal inputted via an input end of the loop optical fiber to one end thereof, and outputting the laser signal to one output end of the loop optical fiber via one output end thereof. ### Claim 7 (depends on 6) The apparatus according to claim 6, wherein: at a first time point, the laser diode outputs the first wavelength pulse; when entering a second time point from the first time point, the first wavelength pulse passes the external reflector, a sideband of the first wavelength pulse is reflected via the external reflector to the laser diode to form the second wavelength pulse, and the external reflector removes the first wavelength pulse; when entering a third time point from the second time point, the second wavelength pulse falls within a retrieval period in which the laser diode is turned off to form the second wavelength picosecond short pulse, and laser signal strength of the second wavelength picosecond short pulse is amplified via the laser diode; when entering a fourth time point from the third time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted to the external reflector; when entering a fifth time point from the fourth time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted via the external reflector to the wavelength filter; and when entering a sixth time point from the fifth time point, the wavelength filter removes the laser signal having the first wavelength pulse, and outputs the single short-pulse laser signal having the second wavelength picosecond short pulse. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the laser adjusts a wavelength of a main wavelength in the first wavelength pulse through temperature control to correspondingly adjust a wavelength of the first wavelength pulse, and the main wavelength in the first wavelength pulse is a nanosecond optical source. ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the pulse driver modulator provides a modulation range of between 1 and 1,000,000 times/second (Hz), and a pulse width range of between 1 ns and 100 μs. ### Claim 10 (depends on 9) The apparatus according to claim 9, wherein the laser diode for generating the laser signal having the main wavelength in the first wavelength in nanoseconds outputs a wavelength range of between 800 nm and 1600 nm. ### Claim 11 (depends on 10) The apparatus according to claim 10, wherein the optical fiber coupler has a light field division rate of 1% to 99% for beam-splitting the nanosecond laser signal. ### Claim 12 (depends on 11) The apparatus according to claim 11, wherein the reflection coupler has a light field division rate of 1% to 99% for beam-splitting the laser signal. ### Claim 13 (depends on 12) The apparatus according to claim 12, wherein the sideband filter has a filter range of 800 nm to 1600 nm; the laser signal inputted at an 11th end is filtered by the sideband filter to select the sideband having the first wavelength pulse to form the second wavelength pulse; and after outputting the second wavelength pulse by one output end of the sideband filter, the second wavelength pulse sequentially passes through the reflection coupler and the optical fiber coupler to return to the laser diode. ### Claim 14 An apparatus for generating a short-pulse laser using a temporally modulated sideband gain, comprising: at least one pulse driver modulator; a laser diode, having one end connected to the pulse driver modulator, and having a nanosecond pulse repetition rate and a pulse width of a programmable semiconductor optical output; an external reflector, having one input end connected to one output end of the laser diode; and a wavelength filter, having one end connected to one output end of the external reflector, for blocking a long-pulse laser signal having a first wavelength pulse, and outputting a single short-pulse laser signal having a second wavelength pulse at one end thereof; wherein, the external reflector comprises: an extension optical fiber, having one end connected to one end of the laser diode; and a second wavelength reflector, having one end connected to one end of the extension optical fiber and one other end connected to a 4th output of the external reflector. ### Claim 15 (depends on 14) The apparatus according to claim 14, wherein: at a first time point, the laser diode outputs the first wavelength pulse; when entering a second time point from the first time point, the first wavelength pulse passes the external reflector, a sideband of the first wavelength pulse is reflected via the external reflector to the laser diode to form the second wavelength pulse, and the external reflector removes the first wavelength pulse; when entering a third time point from the second time point, the second wavelength pulse falls within a retrieval period in which the laser diode is turned off to form the second wavelength picosecond short pulse, and laser signal strength of the second wavelength picosecond short pulse is amplified via the laser diode; when entering a fourth time point from the third time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted to the external reflector; when entering a fifth time point from the fourth time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted via the external reflector to the wavelength filter; and when entering a sixth time point from the fifth time point, the wavelength filter removes the laser signal having the first wavelength pulse, and outputs the single short-pulse laser signal having the second wavelength picosecond short pulse. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein the laser adjusts a wavelength of a main wavelength in the first wavelength pulse through temperature control to correspondingly adjust a wavelength of the first wavelength pulse, and the main wavelength in the first wavelength pulse is a nanosecond optical source. ### Claim 17 (depends on 16) The apparatus according to claim 16, wherein the pulse driver modulator provides a modulation range of between 1 and 1,000,000 times/second (Hz), and a pulse width range of between 1 ns and 100 μs. ### Claim 18 (depends on 17) The apparatus according to claim 17, wherein the laser diode for generating the laser signal having the main wavelength in the first wavelength in nanoseconds outputs a wavelength range of between 800 nm and 1600 nm. ### Claim 19 (depends on 18) The apparatus according to claim 18, wherein the second wavelength reflector is an optical fiber grating or a coated optical fiber for partially reflecting the second wavelength pulse inputted into the second wavelength reflector, and transmitting the partially reflected second wavelength pulse via the extension optical fiber to one end of the external reflector. ### Claim 20 An apparatus for generating a short-pulse laser using a temporally modulated sideband gain, comprising: at least one pulse driver modulator; a laser diode, having one end connected to the pulse driver modulator, and having a nanosecond pulse repetition rate and a pulse width of a programmable semiconductor optical output; an external reflector, having one input end connected to one output end of the laser diode; and a wavelength filter, having one end connected to one output end of the external reflector, for blocking a long-pulse laser signal having a first wavelength pulse, and outputting a single short-pulse laser signal having a second wavelength pulse at one end thereof; wherein, the external reflector comprises: an extension optical fiber, having one end connected to one end of the laser diode;an optical fiber coupler, having one end connected to one end of the extension optical fiber, and one other end connected to one end of the external reflector; and a reflection mirror, having one end connected to one end of the optical fiber coupler. ### Claim 21 (depends on 20) The apparatus according to claim 20, wherein: at a first time point, the laser diode outputs the first wavelength pulse; when entering a second time point from the first time point, the first wavelength pulse passes the external reflector, a sideband of the first wavelength pulse is reflected via the external reflector to the laser diode to form the second wavelength pulse, and the external reflector removes the first wavelength pulse; when entering a third time point from the second time point, the second wavelength pulse falls within a retrieval period in which the laser diode is turned off to form the second wavelength picosecond short pulse, and laser signal strength of the second wavelength picosecond short pulse is amplified via the laser diode; when entering a fourth time point from the third time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted to the external reflector; when entering a fifth time point from the fourth time point, the second wavelength picosecond short pulse having the amplified signal strength is transmitted via the external reflector to the wavelength filter; and when entering a sixth time point from the fifth time point, the wavelength filter removes the laser signal having the first wavelength pulse, and outputs the single short-pulse laser signal having the second wavelength picosecond short pulse. ### Claim 22 (depends on 21) The apparatus according to claim 21, wherein the laser adjusts a wavelength of a main wavelength in the first wavelength pulse through temperature control to correspondingly adjust a wavelength of the first wavelength pulse, and the main wavelength in the first wavelength pulse is a nanosecond optical source. ### Claim 23 (depends on 22) The apparatus according to claim 22, wherein the pulse driver modulator provides a modulation range of between 1 and 1,000,000 times/second (Hz), and a pulse width range of between 1 ns and 100 μs. ### Claim 24 (depends on 22) The apparatus according to claim 22, wherein the laser diode for generating the laser signal having the main wavelength in the first wavelength in nanoseconds outputs a wavelength range of between 800 nm and 1600 nm. ### Claim 25 (depends on 24) The apparatus according to claim 24, wherein the reflection mirror reflects the second wavelength pulse inputted into the second wavelength reflector, and transmits the reflected second wavelength pulse via the optical fiber coupler to one end of the external reflector.