Imra America, Inc.

Boston Laser, Inc.

University of Michigan

University of Colorado

Other

Aisin Seiki Company, Ltd.

Irma America, Inc.

Martin E Fermann

Donald J Harter

Ingmar Hartl

Liang Dong

Gyu Cheon Cho

Almantas Galvanauskas

Gennady Imeshev

Gregg D Sucha

Zhenlin Liu

Lawrence Shah

Mark P Bendett

William S Wong

Xinhua Gu

Min Jiang

Salvatore F Nati

Andrius Marcinkevicius

Ferenc Raksi

Hugh McKay

Libin Fu

Shigeru Suzuki

Antoine Jean Gilbert Rolland

Kevin F Lee

Naoya Kuse

Thomas R Schibli

Michelle L Stock

Axel Ruehl

Yuzuru Uehara

Gyu Choen Cho

Ka K Wong

Marco Marangoni

Takashi Hori

Xinhu Gu

Valery Kozlov

Marco Cassinerio

Douglas Bull

Tomohiro Tetsumoto

Jie Jiang

Jorge W Jimenez

Yihan Li

Davide Gatti

Jens Bethge

Hugh A Mckay

A pulse transformer for modifying the amplitude and phase of short optical pulses includes a pulse source and an adaptively controlled stretcher or compressor including at least one fiber Bragg grating (FBG) configured to receive pulses from the pulse source and having a first second-order dispersion parameter (D). The pulse transformer further includes at least one optical amplifier configured to receive pulses from the FBG and a compressor configured to receive pulses from the at least one optical amplifier. The compressor has a second second-order dispersion parameter (−D), an absolute value of the first second-order dispersion parameter (|D|) and an absolute value of the second second-order dispersion parameter (|−D|) that are substantially equal to one another to within 10%.

Precision light source

Systems and methods for precision control of microresonator (MR) based frequency combs can implement optimized MR actuators or MR modulators to control long-term locking of carrier envelope offset frequency, repetition rate, or resonance offset frequency of the MR. MR modulators can also be used for amplitude noise control. MR parameters can be locked to external reference frequencies such as a continuous wave laser or a microwave reference. MR parameters can be selected to reduce cross talk between the MR parameters, facilitating long-term locking. The MR can be locked to an external two wavelength delayed self-heterodyne interferometer for low noise microwave generation. An MR-based frequency comb can be tuned by a substantial fraction or more of the free spectral range (FSR) via a feedback control system. Scanning MR frequency combs can be applied to dead-zone free spectroscopy, multi-wavelength LIDAR, high precision optical clocks, or low phase noise microwave sources.

Compact microresonator frequency comb

In an example amplifier system, an input pulse train is passed through an optical stage that splits each pulse into two or more pulses. These divided pulses are then injected into at least two amplifiers for amplification. The amplified pulses are subsequently passed back through the same optical stage in order to combine the pulses back into one high energy pulse. The amplifier system can use time division multiplexing (TDM) and/or spatial division multiplexing (SDM) to produce, e.g., four pulses in conjunction with two amplifiers and propagation through two optical beam splitters, which are coherently combined into a single output pulse after amplification. The amplifiers can comprise fiber amplifiers or bulk amplifiers.

Utilization of time and spatial division multiplexing in high power ultrafast optical amplifiers

Examples of compact control electronics for precision frequency combs are disclosed. Application of digital control architecture in conjunction with compact and configurable analog electronics provides precision control of phase locked loops with reduced or minimal latency, low residual phase noise, and/or high stability and accuracy, in a small form factor.

Precision frequency combs

Systems and methods for stabilizing mid-infrared light generated by difference frequency mixing may include a mode locked Er fiber laser that generates pulses, which are split into a pump arm and a wavelength shifting, signal arm. Pump arm pulses are amplified in Er doped fiber. Shifting arm pulses are amplified in Er doped fiber and shifted to longer wavelengths in Raman-shifting fiber or highly nonlinear fiber, where they may be further amplified by Tm doped fiber, and then optionally further wavelength shifted. Pulses from the two arms can be combined in a nonlinear crystal such as orientation-patterned gallium phosphide, producing a mid-infrared difference frequency, as well as nonlinear combinations (e.g., sum frequency) having near infrared and visible wavelengths. Optical power stabilization can be achieved using two wavelength ranges with spectral filtering and multiple detectors acquiring information for feedback control. Controlled fiber bending can be used to stabilize optical power.

Stable difference frequency generation using fiber lasers

Examples of systems and methods for integrated photonic broadband microwave transceivers are disclosed based on integrated coherent dual optical frequency combs. In some cases, when the system is configured as a transmitter, multiple radio frequency (RF) carriers can be generated, which can either be encoded independently, or used for broadcasting the same information into different bands. In some cases, when the system is configured as a receiver, the spectrum of the input signal can be sliced into several spectral segments for low-bandwidth detection and analysis. In some systems, the optics-related functionalities can be achieved via integrated optic technology, for example based on silicon photonics, providing tremendous possibilities for mass-production with significantly reduced system footprint.

Integrated photonic microwave transceiver system

Low phase noise radio frequency (RF) sources generated by voltage controlled oscillators (VCOs) are described. Optical modulators driven by a VCO may be used to generate optical side-bands to cw lasers. The spectral extent of said side-bands can be increased via frequency broadening in highly nonlinear waveguides. Free running mode locked low phase noise comb oscillators can be used as reference oscillators to generate beat signals between those side-bands and individual comb modes at distal spectral regions, thereby creating an error signal used to reduce the phase noise of VCOs and the generation of low phase noise RF signals. VCO phase noise may be reduced by using free-running modelocked comb lasers phase locked to external frequency references, by omitting a reference comb and using a nonlinear interferometer for generating an error signal, or by locking a slave comb to the modulation frequency of an intra-cavity modulator driven by the VCO.

Systems and methods for low noise frequency multiplication, division, and synchronization

The invention describes classes of robust fiber laser systems usable as pulse sources for Nd: or Yb: based regenerative amplifiers intended for industrial settings. The invention modifies adapts and incorporates several recent advances in FCPA systems to use as the input source for this new class of regenerative amplifier.

Yb: and Nd: mode locked oscillators and fiber systems incorporated in solid-state short pulse laser systems

By compensating polarization mode-dispersion as well chromatic dispersion in photonic crystal fiber pulse compressors, high pulse energies can be obtained from all-fiber chirped pulse amplification systems. By inducing third-order dispersion in fiber amplifiers via self-phase modulation, the third-order chromatic dispersion from bulk grating pulse compressors can be compensated and the pulse quality of hybrid fiber/bulk chirped pulse amplification systems can be improved. Finally, by amplifying positively chirped pulses in negative dispersion fiber amplifiers, a low noise wavelength tunable seed source via anti-Stokes frequency shifting can be obtained.

All-fiber chirped pulse amplification systems

Various embodiments include large cores fibers that can propagate few modes or a single mode while introducing loss to higher order modes. Some of these fibers are holey fibers that comprise cladding features such as air-holes. Additional embodiments described herein include holey rods. The rods and fibers may be used in many optical systems including optical amplification systems, lasers, short pulse generators, Q-switched lasers, etc. and may be used for example for micromachining.

Single mode propagation in fibers and rods with large leakage channels

This disclosure relates to polarizing optical fibers and polarization maintaining optical fibers, including active and/or passive implementations. An embodiment includes a polarizing (PZ) optical fiber that includes stress applying parts (SAPs) disposed in a first cladding region, the SAPs comprising a material with a thermal expansion coefficient, &#x3b1;. A core region is at least partially surrounded by cladding features and the SAPs. The core includes glass with a thermal expansion coefficient, &#x3b1;. The arrangement of the SAPs satisfies: R=d/D, where Dis the SAP center to core center distance, and dis the average SAP diameter, and d&#x3b1;=|&#x3b1;&#x2212;&#x3b1;|, and where Rsc and d&#x3b1; may be sufficiently large to induce stress birefringence into the core and to provide for polarized output. Active fibers in which a portion of the fiber is doped may be implemented for application in fiber lasers, fiber amplifiers, and/or optical pulse compressors.

Polarizing and polarization maintaining leakage channel fibers

Frequency standards based on mode-locked fiber lasers, fiber amplifiers and fiber-based ultra-broad bandwidth light sources, and applications of the same.

Laser based frequency standards and their applications

In one aspect, the present disclosure describes a fiber laser system for the generation and delivery of femtosecond (fs) pulses in multiple wavelength ranges. For improved versatility in multi-photon microscopy, an example of a dual wavelength fiber system based on Nd fiber source providing gain at 920 and 1060 nm is described. An example of a three-wavelength system is included providing outputs at 780 nm, 940 nm, and 1050 nm. The systems include dispersion compensation so that high quality fs pulses are provided for applications in microscopy, for example in multiphoton microscope (MPM) systems.

Multi-wavelength, ultrashort pulse generation and delivery, with applications in microscopy

Examples of robust self-starting passively mode locked fiber oscillators are described. In certain implementations, the oscillators are configured as Fabry-Perot cavities containing an optical loop mirror on one cavity end and a bulk mirror or saturable absorber on the other end. The loop mirror can be further configured with an adjustable line phase delay to optimize modelocking. All intra-cavity fiber(s) can be polarization maintaining. Dispersion compensation components such as, e.g., dispersion compensation fibers, bulk diffraction gratings or fiber Bragg gratings may be included. The oscillators may include a bandpass filter to obtain high pulse energies when operating in the similariton regime. The oscillator output can be amplified and used whenever high power short pulses are required. For example the oscillators can be configured as frequency comb sources or supercontinuum sources. In conjunction with repetition rate modulation, applications include dual scanning delay lines and trace gas detection.

Compact fiber short pulse laser sources

A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Peak power handling capability of fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. Dispersive pulse stretching in the presence of self-phase modulation and gain results in the formation of high-power parabolic pulses. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used. Positive dispersion optical amplifiers are used to improve transmission characteristics. An optical communication system utilizes a Raman amplifier fiber pumped by a train of Raman-shifted, wavelength-tunable pump pulses, to thereby amplify an optical signal which counterpropagates within the Raman amplifier fiber with respect to the pump pulses.

Modular, high energy, widely-tunable ultrafast fiber source

Growing community of inventors

Dexter, MI, United States of America

Martin E Fermann