Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with the capability of switching between a modelocked pulse operating mode and an amplification operating mode. The operating modes are carried out through the application of a time-dependent bias voltage, having waveforms as described herein, to an electro-optical device positioned along the optical axis of the resonator.

Apparatuses and methods are disclosed for applying laser energy having desired pulse characteristics, including a sufficiently short duration and/or a sufficiently high energy for the photomechanical treatment of skin pigmentations and pigmented lesions, both naturally-occurring (e.g., birthmarks), as well as artificial (e.g., tattoos). The laser energy may be generated with an apparatus having a resonator with the capability of switching between a modelocked pulse operating mode and an amplification operating mode. The operating modes are carried out through the application of a time-dependent bias voltage, having waveforms as described herein, to an electro-optical device positioned along the optical axis of the resonator.

A mode-locked laser comprising circuitry configured to drive an electro-optic modulator (EOM) in the mode-locked laser with a drive waveform, the drive waveform being a phase-coherent sinusoidal waveform at a frequency equal to a repetition rate of the mode-locked laser, a phase-coherent pulsed waveform at a frequency equal to the repetition rate of the mode-locked laser, or a phase-coherent sinusoidal waveform at a frequency equal to half of the repetition rate of the mode-locked laser.

A synchronized laser system for illuminating a sample with first and second laser light pulses, said system comprising: a trigger, said trigger being operative to issue first and second trigger signals, said first and second trigger signals being emitted at an adjustable frequency with a predetermined delay therebetween; a first tunable mode-locked laser operative for emitting said first laser light pulses in response to receiving a train of said first trigger signals, a first wavelength of said first laser light pulses being dependent on said adjustable frequency in accordance with a first wavelength-frequency relationship; a second tunable mode-locked laser operative for emitting said second laser light pulses in response to receiving a train of said second trigger signals, a second wavelength of said second laser light pulses being dependent on said adjustable frequency in accordance with a second wavelength-frequency relationship; wherein said predetermined delay is such that said first and second laser light pulses are emitted so as to arrive substantially simultaneously in said sample; and said first and second wavelength-frequency relationships are selected to result in a predetermined relationship between said first and second wavelengths at each frequency.

The present invention relates to a light source device and a measuring device which use a change in mode-locked resonated output light over time using a change in a cycle of an electrical signal corresponding to a change in the intensity of the output light according to a mode locking condition for each of different light paths in a resonator. The light source device includes an electrical signal generator configured to control the intensity of an optical signal from the light source device, and an optical gain unit controlled by periodic electrical signals having cycles calculated by dividing a round-trip time of photons corresponding to each of different light paths by an integer multiple. The intensity of the optical signal is controlled by the optical gain unit.

Disclosed herein is a single pulse laser apparatus which includes a first mirror and a second mirror disposed at both ends of the single pulse laser apparatus and having reflectivities of a predetermined level or more; a gain medium rotated at a predetermined angle and configured to oscillate a laser beam in a manual mode-locking state; a linear polarizer configured to output a beam having a specific polarized component of the oscillated laser beam; an etalon configured to adjust a pulse width of the oscillated laser beam; and an electro-optic modulator configured to perform Q-switching and single pulse switching.

Generally discussed herein are systems, devices, and methods for locking an optical frequency comb. A device may include comb error measurement and control circuitry to receive a beat tone and carrier envelope offset of an optical frequency comb and provide a fast and slow repetition rate control and a fast and slow carrier envelope offset control. The repetition rate controls and carrier envelope offset controls to control actuators of an optical frequency comb generator.

An apparatus can be provided which can include a laser arrangement which can be configured to provide a laser radiation, and can include an optical cavity. The optical cavity can include a dispersive optical first arrangement which can be configured to receive and disperse at least one first electro-magnetic radiation so as to provide at least one second electro-magnetic radiation. Such cavity can also include an active optical modulator second arrangement which can be configured to receive and modulate the at least one second radiation so as to provide at least one third electro-magnetic radiation. The optical cavity can further include a dispersive optical third arrangement which can be configured to receive and disperse at least one third electro-magnetic radiation so as to provide at least one fourth electro-magnetic radiation. For example, actions by the first, second and third arrangements can cause a spectral filtering of the fourth electro-magnetic radiation(s) relative to the first electro-magnetic radiation(s). The laser radiation can be associated with the fourth radiation(s), and a wavelength of the laser radiation can be controlled by the spectral filtering caused by the actions by the first, second and third arrangements.

A method of generating laser pulses (1) includes: creating a circulating light field in resonator device (11) having resonator length L and an intra-cavity dispersion and configured for supporting light field resonator modes, and generating a pulse train of laser pulses (1) by a mode-locking mechanism. Laser pulses (1) are generated with a repetition frequency and provide a frequency comb with carrier frequency .sub.o and comb modes in frequency space. The intra-cavity dispersion is selected such that round trip phases have a dependency on frequency according to

[00001]$\left(\right)=.Math..Math.m\left(\sqrt{1+4.Math..Math.\frac{-{}_0}{m.Math..Math.{}_r}}-1\right)+\frac{L}{c}.Math.{}_0$

wherein m is an integer providing effective repetition rate (m.sub.r) in combination with mode spacing .sub.r at optical carrier frequency (.sub.o), and the mode-locking mechanism provides a coupling of the resonator modes whereby frequency difference (n=.sub.n+1.sub.n) between neighboring mode frequencies (.sub.n, .sub.n+1) is a linear function of mode frequency number n. Furthermore, a spectroscopy method for investigating a sample, a laser pulse source apparatus and a spectroscopy apparatus are described.

A method of interrogating an absorbing sample includes using a mode-locked laser mode-locked in both a clock-wise (CW) and a counter-clock wise (CCW) direction to generate first and second optical pulses having different repetition rates. One of the first and second optical pulses is directed in a CW direction and the other of the first and second optical pulses is directed in the CCW direction. The first optical pulses are transmitted through the absorbing sample to probe the absorbing sample while the second optical pulses are transmitted through the absorbing sample to act as a local oscillator. An interference pattern produced by interference between the first and second optical pulses is detected after traversing the absorbing sample.