Valentin Gapontsev - Worcester MA, US Igor Samartsev - Westborough MA, US
Assignee:
IPG Photonics Corporation - Oxford MA
International Classification:
H01S 3/067 G02B 6/14
US Classification:
372 6, 385 28
Abstract:
A high power fiber laser system emitting a substantially diffraction limited beam with a Gaussian intensity profile includes a single mode (“SM”) neodymium fiber pump source outputting a SM pump light; a seed laser operative to emit a SM signal light at a wavelength greater than that of the pump light; a SM DWM receiving and multiplexing the SM pump and signal lights. The disclosed system further includes a booster fiber amplifier which is configured with a frustoconically-shaped ytterbium (“Yb”) doped core receiving the pump and signal lights and configured with a small diameter input end which supports only a SM and a large diameter output end which is capable of supporting the SM and high order modes (:HOM”). The booster further has a cladding surrounding and coextending with the core, the core being configured for having intensity profiles of respective SMs of pump and signal lights overlap one another so that an overlap integral substantially equals to one (1) along an entire length of the core. The SM of the light signal extracts substantially the entire energy from the pump mode leaving the HOMs without amplification necessary to affect a quality of the diffraction limited beam of the system in a MW peak power range and hundreds of watt average power range.
Method And Apparatus For Differentially Controlling Population Inversion In Gain Medium
Sergey Maryashin - Burbach, DE Andre Unt - Burbach, DE Igor Samartsev - Westborough MA, US Vldmimir Antonenko - Fryazino, RU
Assignee:
IPG Photonics Corporation - Oxford MA
International Classification:
H01S 3/11
US Classification:
372 25
Abstract:
A method and apparatus are operative to control the desired level of population inversion in a gain medium having an amplified spontaneous emission (ASE) spectrum which is characterized by distinct short- and long-wavelength regions. The control is realized by the apparatus configured to determine a relationship between the regions of the ASE spectrum represented by respective frequencies which are filtered by respective frequency discriminators. The apparatus includes a controller operative to process the filtered frequencies by determining a relationship between amplitudes of the respective filtered frequencies which represents a measured level of population inversion. Upon mismatch between the measured level and desired level of the population inversion, a control signal is coupled into a pulse generator or pump or both. In response, the pulse generator may output a pulse, or/and the pump may he completely shut down to lower the level of the measured inversion.
Method For Assembling High Power Fiber Laser System And Module Realizing The Method
Igor Samartsev - Westborough MA, US Victor Ilyashenko - Northborough MA, US Davone Keovongmanysar - Oxford MA, US
Assignee:
IPG Photonics Corporation - Oxford MA
International Classification:
H01S 3/067 B32B 37/14 B32B 37/12
US Classification:
372 6, 156 60
Abstract:
A method for arranging a high power fiber laser system includes spiraling an active fiber in a housing with a diameter of spiral gradually decreasing towards the center of th housing. The method further includes coupling the opposite free ends of the spiraled active fiber to respective passive fibers providing optical communication between the active fiber and discrete components. Thereafter, the passive fibers with the discrete components are arranged next to inner spirals of the active fiber.
Ultrafast Pulse Laser System With Multiple Pulse Duration Fast Switch
- OXFORD MA, US David CLARK - Westborough MA, US Igor SAMARTSEV - Westborough MA, US Joe ANTAS - Spencer MA, US Justin BARSALOU - Charlton MA, US
Assignee:
IPG PHOTONICS CORPORATION - OXFORD MA
International Classification:
H01S 3/127 H01S 3/23 H01S 3/16
Abstract:
A CPA ultrashort pulse laser system is configured with a beam splitter dividing each ultrashort pulse from a seed laser into at least two replicas which propagate along respective replica paths. Each replica path includes an upstream dispersive element stretching respective replicas to different pulse durations. The optical switches are located in respective replica paths upstream or downstream from upstream dispersive elements. Each optical switch is individually controllable to operate at a high switching speed between “on” and “off” positions so as to selectively block one of the replicas or temporally separate the replicas at the output of the switching assembly. The replicas are so stretched that a train of high peak power ultrashort pulses each are output with a pulse duration selected from a fs ns range and peak power of up to a MW level.
High Power Cladding Pumped Single Mode Fiber Raman Laser
A Raman fiber laser source is configured with a feeding fiber delivering MM pump radiation to an inner cladding of double-clad MM Raman fiber laser. The MM pump beam radiation has a sufficient power to produce Raman scattering in the MM Raman fiber converting the pump radiation to a MM signal radiation at a Raman-shifted wavelength λram which is longer than a wavelength λpump of the pump radiation. The Raman laser source further has a pair of spaced reflectors defining therebetween a resonator for the signal radiation at a 1Stokes wavelength and flanking at least part of the MM core of the Raman fiber which is provided with a central core region which is doped with impurities for enhancing Raman process. The reflectors and central core region are dimensioned to correspond to the fundamental mode of the MM signal radiation which is output from the Raman fiber with an Mfactor ≤1.1 and in a power range between a few kW and tens of kW.
Ultrafast Pulse Laser System Utilizing Intensity Pulse Shape Correction
- Oxford MA, US Igor SAMARTSEV - Westborough MA, US
International Classification:
H01S 3/13 H01S 3/067 H01S 3/10
Abstract:
The ultrafast pulse fiber laser system is configured with scalable output power and operative to reduce degradation of pulse integrity. The disclosed laser system is configured to suppress the pulse distortion through improvement of initial pulse contrast between main and side pulses and improved pulse shape using chirped pulse amplification and a fast intensity modulator driver by a corrected electrical signal that is generated from the original optical signal. The structure providing the improvement includes the photodiode, which is operative to measure the chirped optical pulse and convert it to the electrical signal, and analog electronics that quickly converts the electrical signal to the required signal that suppress the side pulses.
- OXFORD MA, US Bruce JENKET - Worcester MA, US Anton DROZHZHIN - Avon CT, US George VENUS - Oxford MA, US Igor SAMARTSEV - Westborough MA, US Dmitry PESTOV - Oxford MA, US Anton RYABTSEV - Oxford MA, US
International Classification:
H01S 3/00 H01S 3/10 H01S 3/13 H01S 3/08 H01S 3/23
Abstract:
The ultra-short pulse chirped pulse amplification (CPA) laser system and method of operating CPA laser system include outputting nearly transform limited (TL) pulses by a mode locked laser. The system and method further include temporarily stretching the TL pulses by a first Bragg grating providing thus each stretched pulse with a chirp which is further compensated for in a second Bragg grating operating as as a compressor. The laser system and method further include a pulse shaping unit measuring a spectral phase across the recompressed pulse and further adjusting the deviation of the measured spectral phase from that of the TL pulse by generating a corrective signal. The corrective signal is applied to the array of actuators coupled to respective segments of one of the BGs which are selectively actuated to induce the desired phase change, with the one BG thus operating as both stretcher/compressor and pulse shaper.
- Oxford MA, US Dmitry Pestov - Westborough MA, US Vadim Lozovoy - Marlborough MA, US Igor Samartsev - Westborough MA, US
International Classification:
H01S 3/067 H01S 3/00 H01S 3/11 H01S 3/08
Abstract:
A pulse configurable laser unit is an environmentally stable, mechanically robust, and maintenance-free ultrafast laser source for low-energy industrial, medical and analytical applications. The key features of the laser unit are a reliable, self-starting fiber oscillator and an integrated programmable pulse shaper. The combination of these components allows taking full advantage of the laser's broad bandwidth ultrashort pulse duration and arbitrary waveform generation via spectral phase manipulation. The source can routinely deliver near-TL, sub-60 fs pulses with megawatt-level peak power. The output pulse dispersion can be tuned to pre-compensate phase distortions down the line as well as to optimize the pulse profile for a specific application.