A laser system generates laser pulses having a determined carrier-envelope-offset, CEO. The laser system includes a Cr-doped II-VI based laser oscillator system having a resonator cavity, which emits laser pulses having a peak power of at least 0.75 MW. The laser system further includes a nonlinear optical element for spectrally broadening at least a part of the emitted laser pulses irradiated onto the nonlinear optical element to provide the laser pulses with octave-spanning spectral components, and a frequency-doubling element for generating second harmonic spectral components of at least a part of the octave-spanning spectral components. In addition, the laser system includes an f-2f-interferometry device for generating a beating signal of at least a part of the overlapping spectral components exiting the frequency-doubling element and interfering with each other at the f-2f-interferomtry device and for determining and/or controlling the CEO of the emitted laser pulses based on the beating signal.

A laser oscillator system includes a resonator cavity for confining an intra-cavity laser beam. The laser oscillator system further includes a Cr-doped II-VI gain medium arranged within the resonator cavity and an imaging unit forming part of the resonator cavity. The imaging unit is configured to decouple a spot size of the intra-cavity laser beam at the gain medium from an intra-cavity length of the resonator cavity. Moreover, the resonator cavity and the imaging unit are configured such that the laser oscillator system emits laser pulses at a repetition rate of 50 MHz or less. Further, a laser system and methods for generating light pulses having spectral components at a wavelength of at least 2 ?m are disclosed.

The present invention provides systems and methods for optical frequency comb generation with self-generated optical harmonics in mode-locked lasers for detecting the carrier envelope offset frequency. The mode-locked laser outputs an optical frequency comb and a harmonic output. The harmonic output provides an optical heterodyne resulting in a detectable beat note. A carrier envelope offset frequency detector detects the beat note and generates an optical frequency comb signal. The signal can be used to stabilize the optical frequency comb output.

The present invention provides systems and methods for producing short laser pulses that are amplified and spectrally broadened in a bulk gain media. The bulk material, having laser gain and nonlinear properties, is concurrently exposed to an optical pump input and a seed input, the pump power being sufficient to amplify and spectrally broaden the seed pulse.

Provided is a laser resonator for generating a laser light by absorbing energy from outside. The laser resonator includes a metal body and a gain medium layer having a ring shape. The gain medium layer of a ring shape may be provided on the metal body and may generate the laser light by a plasmonic effect.

The present disclosure provides an optical sub-system for a passive, mode-locked laser optical system. The optical sub-system may include a graphene-based saturable absorber and an optical device configured to control dispersion properties of the laser optical system. The graphene-based saturable absorber may be supported by the optical device.

Systems and methods described herein may include a first semiconductor layer with a first lattice constant, a rare earth pnictide buffer epitaxially grown over the first semiconductor, wherein a first region of the rare earth pnictide buffer adjacent to the first semiconductor has a net strain that is less than 1%, a second semiconductor layer epitaxially grown over the rare earth pnictide buffer, wherein a second region of the rare earth pnictide buffer adjacent to the second semiconductor has a net strain that is a desired strain, and wherein the rare earth pnictide buffer may comprise one or more rare earth elements and one or more Group V elements. In some examples, the desired strain is approximately zero.

A structure can include a III-N layer with a first lattice constant, a first rare earth pnictide layer with a second lattice constant epitaxially grown over the III-N layer, a second rare earth pnictide layer with a third lattice constant epitaxially grown over the first rare earth pnictide layer, and a semiconductor layer with a fourth lattice constant epitaxially grown over the second rare earth pnictide layer. A first difference between the first lattice constant and the second lattice constant and a second difference between the third lattice constant and the fourth lattice constant are less than one percent.

A multiple frequency comb source apparatus (100) for simultaneously creating a first laser pulse sequence representing a first frequency comb (1) and at least one further laser pulse sequence representing at least one further frequency comb (2), wherein at least two of the first and at least one further pulse sequences have different repetition frequencies, comprises a laser resonator device (10) comprising multiple resonator mirrors including first end mirrors EM.sub.1,OC.sub.1 providing a first laser resonator (11), a laser gain medium (21, 22) being arranged in the laser resonator device (10), and a pump device (30) being arranged for pumping the laser gain medium (21), wherein the laser resonator device (10) is configured for creating the first and at least one further laser pulse sequences by pumping and passively mode-locking the laser gain medium (21), the resonator mirrors of the laser resonator device (10) include further end mirrors EM.sub.2, OC.sub.2 providing at least one further laser resonator (12), the first laser resonator (11) and the at least one further laser resonator (12) share the laser gain medium (21), resonator modes of the first laser resonator (11) and the at least one further laser resonator (12) are displaced relative to each other, wherein the resonator modes are located in the laser gain medium (21) at separate beam path spots, and at least one of the first and further end mirrors EM.sub.1, EM.sub.2, OC.sub.1, OC.sub.2 is adjustable so that the repetition frequency of at least one of the first and at least one further laser pulse sequences can be set independently from the repetition frequency of the other one of the first and at least one further laser pulse sequences. Furthermore, a spectroscopic measuring method, a spectroscopy apparatus and a multiple frequency comb generation method are described.

The present disclosure provides a method of optimising an optical system of a mode-locked laser oscillator or a regenerative, multi-pass or single pass amplifier. The method may include the steps of identifying crystallographic axes of an active laser gain medium crystal, cutting the crystal, and orienting the crystal in the optical system in a predetermined orientation relative to a propagation vector of a laser pulse depending on the required output of the optical system.