The invention relates to scanning pulsed laser systems for optical imaging. Coherent dual scanning laser systems (CDSL) are disclosed and some applications thereof. Various alternatives for implementation are illustrated, including highly integrated configurations. In at least one embodiment a coherent dual scanning laser system (CDSL) includes two passively modelocked fiber oscillators. The oscillators are configured to operate at slightly different repetition rates, such that a difference f.sub.r in repetition rates is small compared to the values f.sub.r1 and f.sub.r2 of the repetition rates of the oscillators. The CDSL system also includes a non-linear frequency conversion section optically connected to each oscillator. The section includes a non-linear optical element generating a frequency converted spectral output having a spectral bandwidth and a frequency comb comprising harmonics of the oscillator repetition rates. A CDSL may be arranged in an imaging system for one or more of optical imaging, microscopy, micro-spectroscopy and/or THz imaging.

A laser resonator includes a gain medium that produces light from pump energy and a variable light attenuator, which receives light and emits either (i) a first light including a continuous series of micropulses, or (ii) a second light including a series of macropulses at spaced time intervals, where each macropulse includes a series of micropulses. Each micropulse has a duration of 0.1 to 10 microseconds, and a duration of each macropulse is less than the time interval between each macropulse, and the micropulses have a frequency of 5 kHz to 40 kHz.

A method of generating fs laser pulses (1), includes steps of creating a circulating light field in a resonator cavity (10) with multiple resonator mirrors (11-18) by pumping at least one gain medium (21, 22) included in the resonator cavity (10), and passing the circulating light field through a first Kerr medium (31) included in the resonator cavity (10), so that the fs laser pulses (1) are formed by self-amplitude modulation of the circulating light field, wherein the resonator cavity (10) includes at least one supplementary Kerr medium (32-36) enhancing the self-amplitude modulation of the circulating light field, and each of the first Kerr medium (31) and the at least one supplementary Kerr medium (32-36) provide different non-linear Kerr lens contributions to the self-amplitude modulation of the circulating light field. Laser pulse source apparatus (100) for generating fs laser pulses (1) is also described.

A laser according to an exemplary embodiment of the present invention includes a pump laser outputting laser light, and a laser resonator including a laser crystal and an acoustic optical modulator and resonating the laser light output from the pump laser, wherein the pump laser is a Nd:YAG, and the laser crystal is Ti:Sapphire.

A laser light-source apparatus includes; a seed light source; a fiber amplifier configured to amplify pulse light output from the seed light source based on gain switching; a solid state amplifier configured to further amplify the resultant pulse light; a nonlinear optical element configured to perform wavelength conversion on the pulse light output from the solid state amplifier; an optical switching element that is disposed between the fiber amplifier and the solid state amplifier and is configured to remove ASE noise; and a control unit. The control unit is configured to control the optical switching element in such a manner that propagation of light is permitted in an output period of the pulse light from the seed light source, and is stopped in a period other than the output period.

An optical device including an acousto-optic modulator (AOM), a laser, an upstream optical fibre extending between the laser and the AOM, a downstream optical fibre located downstream of the AOM and a reflector connected to the fibre downstream of the AOM. The optical device including the upstream fibre is a polarisation-maintaining optical fibre, and/or the downstream fibre is arranged so that a transit time of the optical beam through said downstream fibre from the AOM to the reflecting means is nonzero and shorter than or equal to half an open duration of the AOM, and/or the AOM includes a crystal in which the entrance/exit faces are planar and are at a nonzero angle to each other, and/or at least one of the two entrance/exit faces is at a nonzero angle to a direction of propagation of the acoustic wave in the crystal.

A system includes a first acousto-optic deflector (AOD) for diffracting an incident beam of laser energy to produce and output therefrom a first beam of laser energy and a second beam of laser light, a second AOD arranged to receive the first beam of laser energy and for diffracting the received first beam of laser energy to thereby produce and output therefrom a third beam of laser energy and a fourth beam of laser energy, at least one first beam trap arranged and configured to absorb the second beam of laser energy output from the first AOD, at least one second beam trap arranged and configured to absorb the fourth beam of laser energy output from the second AOD and a controller communicatively coupled to the first AOD and to the second AOD, wherein the controller is configured to operate of the first AOD while not operating the second AOD.

A beam positioner for deflecting a beam path, along which a diffracted beam of linearly polarized laser light is propagatable, within a two-dimensional scan field, the beam positioner includes a first acousto-optic deflectors (AOD) to deflect the beam path within a first one-dimensional scan field extending along a first axis of the two-dimensional scan field, a second AOD to deflect the beam path within a second one-dimensional scan field extending along a second axis of the two-dimensional scan field, a phase retarder arranged between the first AOD and the second AOD and within the beam path along which the beam of laser light is propagatable from the first AOD and a mirror arranged between the first AOD and the second AOD and within the beam path along which the beam of laser light is propagatable from the first AOD.

A method of operating a laser includes, after a laser produces a first pulse, setting an attenuation of an attenuator in the laser such that gain of the laser exceeds losses of the laser to allow the laser to produce a first continuous beam; after the first continuous beam is produced, increasing the attenuation such that losses of the laser exceed a gain of the laser; and after increasing the attenuation, lowering the attenuation such that the laser produces a second pulse. A system for generating a pulse of laser radiation includes an optical modulator controlled by a signal applied to the optical modulator, the modulator connected to a laser, and a control system configured to provide the signal to the modulator according to the method.

A beam positioner for deflecting a beam path, along which a diffracted beam of linearly polarized laser light is propagatable, within a two-dimensional scan field, the beam positioner includes a first acousto-optic deflectors (AOD) to deflect the beam path within a first one-dimensional scan field extending along a first axis of the two-dimensional scan field, a second AOD to deflect the beam path within a second one-dimensional scan field extending along a second axis of the two-dimensional scan field, a phase retarder arranged between the first AOD and the second AOD and within the beam path along which the beam of laser light is propagatable from the first AOD and a mirror arranged between the first AOD and the second AOD and within the beam path along which the beam of laser light is propagatable from the first AOD.