A broadband optical amplifier for operation in the 2 μm visible wavelength band is based upon a single-clad Ho-doped fiber amplifier (HDFA). A compact pump source uses a combination of discrete laser diode with a fiber laser (which may be a dual-stage fiber laser) to create a pump output beam at a wavelength associated with creating gain in the presence of Ho ions (an exemplary pump wavelength being 1940 nm). The broadband optical amplifier may take the form of a single stage amplifier or a multi-stage amplifier, and may utilize a co-propagating pump and/or a counter-propagating pump arrangement.

An amplified hollow-core fiber (HCF) optical transmission system for low latency communications. The optical transmission system comprises a low-latency amplified HCF cable. The low-latency amplified HCF cable comprises multiple HCF segments (or HCF spans). Between consecutive HCF segments, the system comprises low-latency remote optically pumped amplifiers (ROPAs). Each ROPA comprises a gain fiber, a wavelength division multiplexing (WDM) coupler, and an optical isolator. Preferably, the ROPAs are integrated into the HCF cable. Each ROPA is pumped by a remote optical pump source, which provides pump light to the gain fiber. The gain fiber receives an optical transmission signal from the HCF. The WDM coupler combines the pump light with the optical transmission signal, thereby allowing the gain fiber to amplify the optical transmission signal to an amplified transmission signal. The amplified signal is transmitted to another HCF segment through the optical isolator.

Reduction or elimination of negative consequences of reflected stray light from lens surfaces is achieved by propagating a laser beam through an eccentric pupil that excludes the optical axis of the system, which is rotationally symmetric. In such systems, stray light reflections eventually are focused onto the unique optical axis of the system, in either a real or virtual focal region. By using an eccentric pupil, all damage due to focusing of the stray light lies outside of the beam. These focal regions can, e.g., be physically blocked to eliminate beam paths that lead to optical damage, re-pulse beams and parasitic lasing.

A laser system for the generation of ultrashort optical pulses of light including an oscillator emitting low power and negatively chirped optical pulses with a spectral bandwidth W1, a dispersive connecting segment to maintain the sign of the chirp of the pulses of the oscillator, an optical amplifier for amplifying the optical light pulses and a negative group velocity dispersion segment for compensating phase contributions of the whole propagation process. During the propagation from the output of the oscillator to the end of the optical amplifier, the chirp of the light pulses will change once from negative to positive chirp. After a final compression stage ultrashort optical pulses can be generated.

An apparatus is provided, the apparatus comprising: (i) a diode-pumped solid-state laser oscillator configured to generate a pulsed laser beam having predefined beam characteristics corresponding to a current setting selection of a controller; and (ii) an amplifier configured to amplify an energy and modify a beam profile of the pulse laser beam. A beam detector is coupled to the generated beam to monitor a combination of: (i) a beam pulse width; (ii) a beam diameter; and (iii) an energy level, and generates an error signal to be sent back as a feedback signal to the controller. The controller configures the current source to output a correction current to tune the DPSSL oscillator, the wave plate, and the first polarizer to rotate a correction polarization angle and adjust the energy amplification or temporal profile to within a defined performance tolerance.

The technology of this application relates to an optical component constituting a fiber amplifier, a fiber amplifier, and a manufacturing method. The optical component is connected to a gain fiber by using a first fiber, or the optical component is directly connected to the gain fiber. The optical component is connected to one or more second optical components in the fiber amplifier by using a second fiber, and/or the optical component inputs an optical signal or outputs an optical signal amplified by the gain fiber by using the second fiber. Softening temperatures and/or refractive indexes of the first fiber and the second fiber are different, or softening temperatures and/or refractive indexes of the second fiber and the gain fiber are different.

Some embodiments may include a fiber laser including two or more input fibers and an output fiber to deliver a beam to a workpiece, the fiber laser comprising. The fiber laser may include a combiner having ends and a length, wherein the combiner is arranged to release, from its length, a portion of back-reflected light received from the output fiber at an output end of the ends from the combiner, the combiner including: a capillary tube to enclose part of the two or more input fibers at an input end of the ends of the combiner, the capillary tube having ends and a length located between the ends of the capillary tube; and a cladding light stripper (CLS) defined by part of the length of the capillary tube, wherein the CLS provides the release of the portion of the back-reflected light. Other embodiments may be disclosed and/or claimed.

An optical modulator includes an acousto-optic assembly and a thermal management apparatus. The acousto-optic assembly includes: an acousto-optic material; a first side configured to receive an incident light beam; and a second side configured to emit an output light beam based on the incident light beam. The thermal management apparatus includes: a first thermally conductive material in thermal contact with the first side of the acousto-optic assembly; and a second thermally conductive material in thermal contact with the second side of the acousto-optic assembly.

An objective of the present invention is to provide an amplification fiber having a cladding excitation configuration that improves amplification efficiency and an optical amplifier. An amplification fiber (10) according to the present invention is a multi-core amplification fiber having, from one end (E1) to the other end (EE), a plurality of cores (11b) in a cladding (11a), and a total distance from the one end (E1) to the other end (EE) in which rare earth ions are doped differs depending on the types of cores (11b). The cores (11b) are preferably disposed such that the cores of the same type are not adjacent to each other. By arranging the types of the cores in this manner, requirements for inter-core crosstalk can be mitigated since the bands of signal light in the adjacent cores are different. As a result, a density of cladding excitation light can be increased by shortening the inter-core distance, and thus the amplification efficiency can be improved.

A femtosecond laser source according to an embodiment of the present invention includes: a pulse generator that converts a continuous wave laser into an optical pulse train; a burst generator that separates the optical pulse train into a plurality of burst pulses; a pulse amplification and spectral broadening unit that expands the spectrum by amplifying a plurality of burst pulses; and a pulse compressor that compresses a plurality of amplified burst pulses to generate a femtosecond laser with a pulse width of 1 picosecond (10.sup.−12 s) or less.