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 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 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: 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 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.

Abstract: The pulse duration of an iodine laser is adjusted between 400 ps and 20 ns primarily by changing the resonator length in the range of about 2 cm to about 100 cm and secondarily by the ratio of excitation energy to threshold energy of the laser. Iodine laser pulses without pre-pulse and substructure are achieved in that the gas pressure of the laser gas of the iodine laser is adapted to the resonator length in order to limit the band width of the amplification and thus the band width of the pulse to be produced. The longer are the laser pulses to be produced the lower is the pressure chosen. A prerequisite for the above results is that the excitation of the iodine laser occurs extremely rapidly. This is advantageously achieved by photo-dissociation of a perfluoroalkyl iodide as CF.sub.3 I by means of laser providing sufficiently short output pumping pulses, e.g. an excimer laser, as a KrF laser or XeCl laser or a frequency-multiplied Nd-glass or Nd-YAG laser, or a N.sub.2 laser (in combination with t-C.sub.