Abstract: A method of passively enhancing pulsed laser light by coherent addition of laser pulses in an enhancement cavity (20) comprises the steps of generating a sequence of seed laser pulses (1) with a repetition frequency frep and a frequency comb spectrum (3) comprising frequency comb lines (4) with frequency comb line spacings equal to the repetition frequency frep, coupling the seed laser pulses (1) via a first plate-shaped coupling element (25) into an enhancement cavity (20) comprising at least two cavity mirrors (21, 22, 23, 24) having metallic surfaces and spanning a cavity beam path (26) with a resonator length L, wherein the enhancement cavity (20) has a fundamental transverse mode TEM00 and higher-order transverse cavity modes TEMnm, each with a series of cavity resonance frequencies (5), and a cavity offset frequency (6), and coherent superposition of the seed laser pulses (1) in the enhancement cavity (20), so that at least one enhanced circulating cavity pulse (2) per cavity length is generated, wherei

Abstract: A laser pulse sequence measuring method for measuring a delay between a pair of pulses from two laser pulse sequences (1, 2), comprises the steps of creating a first laser pulse sequence (1) of first laser pulses (1A) and a second laser pulse sequence (2) of second laser pulses (2A), and generating a delay signal (3) which represents the delay between the pair of pulses from the first and second laser pulse sequences (1, 2), wherein the step of generating the delay signal (3) includes creating intra-pulse difference frequency generation (IPDFG) pulses (4) by applying intra-pulse difference frequency generation to the first laser pulses (1A) in a difference frequency generation (DFG) medium (21), providing phase-stable reference waveforms (5) based on the IPDFG pulses (4), and electro-optic sampling (EOS) of the electric field of the phase-stable reference waveforms (5) with sampling pulses (6) in an EOS medium (22), wherein the sampling pulses (6) are created based on the second laser pulses (2A), for generat

Abstract: A particle analysis method and apparatus, including a spectrometry-based analysis of a fluid sample (1), comprises the steps of creating a sample light beam S and a probe light beam P with a light source device (10) and periodically varying a relative phase between the sample and probe light beams S, P with a phase modulator device (20), irradiating the fluid sample (1) with the sample light beam S, detecting the sample and probe light beams S, P with a detector device (40), and providing a spectral response of the at least one particle (3), wherein the light source device (10) comprises at least one broadband source, which has an emission spectrum covering a mid-infrared MIR frequency range, and the phase modulator device (20) varies the relative phase with a scanning period equal to or below the irradiation period of irradiating the at least one particle (3, 4).

Abstract: An interferometer apparatus includes a beam splitter arranged for splitting an input beam into a first beam propagating along a first interferometer arm including a deflection mirror and a second beam propagating along a second interferometer arm including a deflection mirror. The first and second interferometer arms have an identical optical path length. A beam combiner is arranged for recombining the first and second beams into a constructive output and a destructive output. In the first interferometer arm compared with the second interferometer arm, one additional Fresnel reflection at an optically dense medium is provided and a propagation of the electromagnetic fields of the first and second beams, when recombined by the beam combiner, results in a wavelength-independent phase difference of ? between the contributions of the two interferometer arms to the destructive output. Furthermore, an interferometric measurement apparatus and an interferometric measurement method are described.

Abstract: A particle analysis method and apparatus, including a spectrometry-based analysis of a fluid sample (1), comprises the steps of creating a sample light beam S and a probe light beam P with a light source device (10) and periodically varying a relative phase between the sample and probe light beams S, P with a phase modulator device (20), irradiating the fluid sample (1) with the sample light beam S, detecting the sample and probe light beams S, P with a detector device (40), and providing a spectral response of the at least one particle (3), wherein the light source device (10) comprises at least one broadband source, which has an emission spectrum covering a mid-infrared MIR frequency range, and the phase modulator device (20) varies the relative phase with a scanning period equal to or below the irradiation period of irradiating the at least one particle (3, 4).

Abstract: An interferometer apparatus for an achromatic interferometric superposition of electromagnetic fields, with a dual beam path interferometer, comprises a beam splitter being arranged for splitting an input beam into a first beam propagating along a first interferometer arm (A1) including at least one deflection mirror and a second beam propagating along a second interferometer arm (A2) including at least one deflection mirror, wherein the first and second interferometer arms have an identical optical path length, and a beam combiner being arranged for recombining the first and second beams into a constructive output and a destructive output, wherein reflective surfaces of the beam splitter and the beam combiner are arranged such that, in the first interferometer arm compared with the second interferometer arm, one additional Fresnel reflection at an optically dense medium is provided and a propagation of the electromagnetic fields of the first and second beams, when recombined by the beam combiner, results in

Abstract: A method of measuring a polarization response of a sample (1), in particular a biological sample, comprises the steps of generating a sequence of excitation waves (2), irradiating the sample (1) with the sequence of excitation waves (2), including an interaction of the excitation waves (2) with the sample (1), so that a sequence of sample waves (3) is generated each including a superposition of a sample main pulse and a sample global molecular fmgerprint (GMF) wave (EGMF(sample)(t)), irradiating a reference sample (1A) with the sequence of excitation waves (2), including an interaction of the excitation waves (2) with the reference sample (1A), so that a sequence of reference waves (3A) is generated each including a superposition of a reference main pulse and a reference GMF wave (EGMF(ref)(t)), optically separating a difference of the sample waves (3) and reference waves (3A) from GMF wave contributions which are common to both of the sample waves (3) and reference waves (3A) in space and/or time, and detect

Abstract: A method of measuring a spectral response of a biological sample (1), comprises the steps generation of probe light having a primary spectrum, irradiation of the sample (1) with the probe light, including an interaction of the probe light and the sample (1), and spectrally resolved detection of the probe light having a modified spectrum, which deviates from the primary spectrum as a result of the interaction of the probe light and the sample (1), said modified spectrum being characteristic of the spectral response of the sample (1), wherein the probe light comprises probe light pulses (2) being generated with a fs laser source device (10). Furthermore, a spectroscopic measuring apparatus is described, which is configured for measuring a spectral response of a biological sample (1).

Abstract: A method of creating difference frequency (DF) laser pulses (1) by difference frequency generation (DFG) comprises the steps of providing ultrashort laser pulses (2) having a spectral bandwidth corresponding to a Fourier limit of below 50 fs and containing first spectral components and second spectral components having larger frequencies than the first spectral components, and driving a DFG process by the ultrashort laser pulses (2) in an optically non-linear crystal (10), wherein the DF laser pulses (1) are generated in the crystal (10) by difference frequencies between the first and second spectral components, resp.

Abstract: A method of measuring a spectral response of a biological sample (1), comprises the steps generation of probe light having a primary spectrum, irradiation of the sample (1) with the probe light, including an interaction of the probe light and the sample (1), and spectrally resolved detection of the probe light having a modified spectrum, which deviates from the primary spectrum as a result of the interaction of the probe light and the sample (1), said modified spectrum being characteristic of the spectral response of the sample (1), wherein the probe light comprises probe light pulses (2) being generated with a fs laser source device (10). Furthermore, a spectroscopic measuring apparatus is described, which is configured for measuring a spectral response of a biological sample (1).

Abstract: A method of spatially splitting a primary radiation beam (1) with a first radiation component (2) including an optical wavelength and a second radiation component (3) having a wavelength shorter than the first radiation component wavelength, said second radiation component (3) having a second or higher harmonic wavelength relative to the optical wavelength, comprises directing the primary radiation beam (1) onto a deflection mirror (10) having a reflective mirror surface (12) and carrying a refractive plate element (20), reflecting the first radiation component (2) at the reflective mirror surface (12) and reflecting the second radiation component (3) at an exposed plate surface (22) of the refractive plate element (20), wherein the reflected radiation components (4, 5) travel along different beam paths.

Abstract: An enhancement resonator (20) being configured for generating intra-resonator laser light (1) by coherent superposition of input laser light, comprises at least three resonator mirrors (21, 22, 23, 24) spanning a ring resonator path in one common resonator plane, said resonator path being free of a laser light amplifying medium, wherein the at least three resonator mirrors (21, 22, 23, 24) include at least two toroidal mirrors and/or at least one cylindrical mirror. Furthermore, a laser device (100) comprising the enhancement resonator (20) and a method of generating intra-resonator laser light (1) are described.

Abstract: An enhancement resonator (20) being configured for generating intra-resonator laser light (1) by coherent superposition of input laser light, comprises at least three resonator mirrors (21, 22, 23, 24) spanning a ring resonator path in one common resonator plane, said resonator path being free of a laser light amplifying medium, wherein the at least three resonator mirrors (21, 22, 23, 24) include at least two toroidal mirrors and/or at least one cylindrical mirror. Furthermore, a laser device (100) comprising the enhancement resonator (20) and a method of generating intra-resonator laser light (1) are described.

Abstract: A method of generating intra-resonator laser light (1) comprises the steps of coupling input laser light (2), e. g.

Abstract: A method of spatially splitting a primary radiation beam (1) with a first radiation component (2) including an optical wavelength and a second radiation component (3) having a wavelength shorter than the first radiation component wavelength, said second radiation component (3) having a second or higher harmonic wavelength relative to the optical wavelength, comprises directing the primary radiation beam (1) onto a deflection mirror (10) having a reflective mirror surface (12) and carrying a refractive plate element (20), reflecting the first radiation component (2) at the reflective mirror surface (12) and reflecting the second radiation component (3) at an exposed plate surface (22) of the refractive plate element (20), wherein the reflected radiation components (4, 5) travel along different beam paths.

Abstract: A method of generating intra-resonator laser light (1) comprises the steps of coupling input laser light (2), e.g.

Abstract: A method of generating pulsed laser light (1) comprises the steps of providing laser light pulses (2, 3) having a predetermined pulse repetition rate (frep) with a laser source device (10), coupling the laser light pulses into an enhancement cavity (21) with a plurality of cavity mirrors (21.1, 21.2, . . . ) and a predetermined cavity length (L), and coherent addition of the laser light pulses (2) in the enhancement cavity so that at least one cavity pulse (1.1, 1.2, . . . ) is formed, wherein the at least one cavity pulse (1.1, 1.2, . . . ) circulating in the enhancement cavity (21) irradiates all of the cavity mirrors (21.1, 21.2, . . . ) with an angle (?) of incidence of more than 45°. Furthermore, a laser device (100) being configured for conducting the method is described.