A modular, compact and widely tunable laser system for the efficient generation of high peak and high average power ultrashort pulses. Peak power handling capability of fiber amplifiers is expanded by using optimized pulse shapes, as well as dispersively broadened pulses. Dispersive pulse stretching in the presence of self-phase modulation and gain results in the formation of high-power parabolic pulses. To ensure a wide tunability of the whole system, Raman-shifting of the compact sources of ultrashort pulses in conjunction with frequency-conversion in nonlinear optical crystals can be implemented, or an Anti-Stokes fiber in conjunction with fiber amplifiers and Raman-shifters are used. Positive dispersion optical amplifiers are used to improve transmission characteristics. An optical communication system utilizes a Raman amplifier fiber pumped by a train of Raman-shifted, wavelength-tunable pump pulses, to thereby amplify an optical signal which counterpropagates within the Raman amplifier fiber with respect to the pump pulses.

Optical component (10) for modulating light field (1) incident thereon, particularly amplitude and/or phase in dependency on intensity (I) thereof, includes stack (11) of refractive layers (12, 13) on substrate (14), made of materials having third-order nonlinearity, and having alternatingly varying refractive indices (n), including linear contribution (n.sub.0) and non-linear contribution (n.sub.2), and determining reflectance and transmittance spectra of the optical component, wherein refractive layers (12, 13) are configured such that reflectance and transmittance of the optical component have a Kerr effect based dependency on intensity (I) of the incident light field with n=n.sub.0+I.Math.n.sub.2, and refractive layers (12, 13) are made of at least one of dielectric and semiconductor layers, wherein non-linear contribution (n.sub.2) is below 10.sup.−12 cm.sup.2/W. A resonator device including the optical component, a method of modulating a light field using the optical component and a method of manufacturing the optical component are described.

A system for optical comb carrier envelope offset frequency control includes a mode-locked oscillator. The mode-locked oscillator produces an output beam using an input beam and one or more control signals. The output beam includes a controlled carrier envelope offset frequency. A beat note generator produces a beat note signal using a portion of the output beam. A control signal generator produces the one or more control signals to set the beat note signal by modulating the intensity of the input beam within the mode locked oscillator. Modulating the intensity comprises using a Mach-Zehnder intensity modulator or using an intensity modulated external laser to affect a gain medium within the mode-locked laser.

A frequency comb laser providing large comb spacing is disclosed. At least one embodiment includes a mode locked waveguide laser system. The mode locked waveguide laser includes a laser cavity having a waveguide, and a dispersion control unit (DCU) in the cavity. The DCU imparts an angular dispersion, group-velocity dispersion (GVD) and a spatial chirp to a beam propagating in the cavity. The DCU is capable of producing net GVD in a range from a positive value to a negative value. In some embodiments a tunable fiber frequency comb system configured as an optical frequency synthesizer is provided. In at least one embodiment a low phase noise micro-wave source may be implemented with a fiber comb laser having a comb spacing greater than about 1 GHz. The laser system is suitable for mass-producible fiber comb sources with large comb spacing and low noise. Applications include high-resolution spectroscopy.

A wavelength-swept optical source is based upon a combination of a coherent source of ultra-short optical pulses, doped fiber amplifier, and specialized dispersive optical medium to create time-stretched pulses. The pulses are broadened to have a spectral bandwidth that covers a wavelength range of interest for a particular wavelength sweeping application and are thereafter subjected to time-stretching within the dispersive optical medium so as to sufficiently separate in time a number of wavelength components within each pulse.

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 minors of the laser resonator device (10) include further end minors 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 minors 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 techniques for improving the rate and efficiency of charge transfer within an integrated circuit configured to receive incident photons. Some aspects of the present disclosure relate to integrated circuits that are configured to induce one or more intrinsic electric fields that increase the rate and efficiency of charge transfer within the integrated circuits. Some aspects of the present disclosure relate to integrated circuits configured to induce a charge carrier depletion in the photodetection region(s) of the integrated circuits. In some embodiments, the charge carrier depletion in the photodetection region(s) may be intrinsic, in that the depletion is induced even in the absence of external electric fields applied to the integrated circuit. Some aspects of the present disclosure relate to processes for operating and/or manufacturing integrated devices as described herein.

A fiber laser device includes a first optical fiber, a second optical fiber, and a third optical fiber configured by polarization maintaining fibers. The first optical fiber includes at least one first part and at least two second parts alternatively disposed with the first part. The first part and the second part adjacent to each other are connected to each other such that a fast axis of the first part coincides with a slow axis of the second part at a connection point. A total length of the first part is equal to a total length of the second parts. A mode field diameter of the first optical fiber is smaller than each of a mode field diameter of the second optical fiber and a mode field diameter of the third optical fiber.

Embodiments relate to a resonator including a graphene layer formed on a support, and a tapered fiber disposed around at least part of the support, close to the graphene layer, wherein the tapered fiber has different paths along which light travels in a region extending from one end and a region extending from the other end, and a passive-mode-locked pulse laser oscillation system including the same.

Apparatus and methods for producing ultrashort optical pulses are described. A high-power, solid-state, passively mode-locked laser can be manufactured in a compact module that can be incorporated into a portable instrument. The mode-locked laser can produce sub-50-ps optical pulses at a repetition rates between 200 MHz and 50 MHz, rates suitable for massively parallel data-acquisition. The optical pulses can be used to generate a reference clock signal for synchronizing data-acquisition and signal-processing electronics of the portable instrument.