Fiber optic amplification includes a photonic crystal fiber coupled to a pump laser through a first coupler. The pump laser emits a first electromagnetic radiation wave into the photonic crystal fiber at a first oscillation frequency and a second electromagnetic radiation wave into the photonic crystal fiber at a second oscillation frequency equaling the first oscillation frequency. The first and second electromagnetic radiation waves interact to generate a signal comprising an electromagnetic radiation wave at a third oscillation frequency and an idler comprising a fourth electromagnetic radiation wave at a fourth oscillation frequency to be generated and amplified through parametric amplification. Parametric amplification is achieved by four wave mixing. The photonic crystal fiber emits a parametric output signal based on the four wave mixing. A nonlinear crystal frequency doubles the parametric output signal through second-harmonic generation.

There is described a fiber laser system generally having a pump laser generating a pump laser beam; and a length of optical fiber optically coupled to the pump laser, the length of optical fiber having: a laser cavity having a cavity path, a first fiber Bragg grating having a first reflectivity profile, a second filter having a second filter profile, and an optical gain region between the first fiber Bragg grating and the second filter along the cavity path, the first reflectivity profile being spectrally detuned from the second filter profile, the first fiber Bragg grating having a first refractive index profile comprising a full width at half maximum bandwidth of at least 0.2 nm and a Gaussian-like apodization, wherein, upon pumping of the optical gain region with the pump laser beam and mode locking of the laser cavity, optical pulses are circulated along the cavity path; and an output.

A light pulse source and method for generating repetitive optical pulses are described. The light pulse source includes a continuous wave cw laser device, an optical waveguide optically coupled with the laser device, an optical microresonator, and a tuning device. The optical microresonator coupling cw laser light via the waveguide into the microresonator, which, may include, a light field in a soliton state with soliton shaped pulses coupled out of the microresonator for providing the repetitive optical pulses. The laser device includes a chip based semiconductor laser, the microresonator and/or the waveguide may reflect an optical feedback portion of light back to the semiconductor laser, which may provide self-injection locking relative to a resonance frequency of the microresonator. The tuning device is arranged for tuning at least one of a driving current and a temperature of the semiconductor laser such that the microresonator may provide the soliton state.

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.

A light pulse source and method for generating repetitive optical pulses are described. The pulse source includes a continuous wave (cw) laser device, an optical waveguide optically coupled with the laser device, an optical microresonator, and a tuning device. The optical microresonator coupling cw laser light via the waveguide into the microresonator, which may include a light field in a soliton state with soliton shaped pulses coupled out of the microresonator for providing the repetitive optical pulses. The laser device includes a chip based semiconductor laser, the microresonator and/or the waveguide may reflect an optical feedback portion of light back to the semiconductor laser, which may provide self-injection locking relative to a resonance frequency of the microresonator. The tuning device is arranged for tuning at least one of a driving current and a temperature of the semiconductor laser such that the microresonator may provide the soliton state.

A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.

A downhole sensing method includes modulating light to form a soliton that propagates through an optical fiber acting as a sensing element that measures a downhole parameter. The method further includes obtaining scattered light created as the soliton propagates through the optic-fiber. The method further includes determining a value for a downhole parameter based on the scattered light, and displaying a representation of the value.

A method and system for delivering laser pulses achieves the delivery of high quality laser pulses at the location of an application. The method includes the steps of: generating laser pulses, amplifying the laser pulses, temporally stretching the amplified laser pulses, and propagating the amplified laser pulses through an optical delivery fiber of desired length, wherein the laser pulses are temporally compressed in the optical delivery fiber and wherein the laser pulses undergo nonlinear spectral broadening in the optical delivery fiber.

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.

Optical pulse sources. In one example, the pulse source includes an optical fiber ring resonator with at least one normal dispersion fiber segment characterized by a positive group velocity dispersion (GVD) per unit length and at least one anomalous dispersion fiber segment characterized by a negative GVD per unit length. In another example, the pulse source includes an optical fiber ring resonator with one or more fiber segments having a positive net group velocity dispersion (GVD); and an intracavity spectral filter optically coupled to the one or more fiber segments. The pulse source is configured to generate one or more optical solitons in the optical fiber ring resonator.