A continuous optical beat laser element for generating terahertz (THz) waves and a laser source using same includes periodically poled lithium niobate (ppLN) crystals arranged along a predetermined direction forming a surface generally parallel to the predetermined direction. A Ti diffused region is applied on the surface and an array of gold nanowires are applied on the Ti diffused region to form a gold metal-insulator-metal (MIM) element that optimizes coupling and channeling of THz radiation from the crystals into the gold nanowires. The system provides a simple, stable, compact and cost-effective THz source using a widely tunable C-band SOA-based laser to excite a non-linear photo-mixer to produce terahertz radiation that ranges from 0.8 to 2.51 THz at room temperature. This laser source can be modified into an all fiber-based THz generator by embedding ppLN crystals in a fiber filament configuration resulting in less absorption and producing high output power.

A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ΔL bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

A combination of microvalves and waveguides may enable the creation of reconfigurable on-chip light sources compatible with planar sample preparation and particle sensing architecture using either single-mode or multi-mode interference (MMI) waveguides. A first type of light source is a DFB laser source with lateral gratings created by the light valves. Moreover, feedback for creating a narrowband light source does not have to be a DFB grating in the active region. A DBR configuration (Bragg mirrors on one or both ends of the active region) or simple mirrors at the end of the cavity can also be used. Alternately, ring resonators may be created using a valve coupled to a bus waveguide where the active gain medium is either incorporated in the ring or inside an enclosed fluid. The active light source may be activated by moving a fluid trap and/or a solid-core optical component defining its active region.

A holder and at least one terminal element that are configured and arranged with respect to one another so as to form a cavity of length ΔL bounded axially by two walls the relative position of which with respect to each other varies in the opposite direction to the variation in ambient temperature, an increase in temperature causing the walls to move closer together and vice versa. A linear structure incorporating the device sees its length decrease when temperature increases and vice versa. Electro-optical transducers comprising a piezoelectric actuator of linear structure that acts on the length of a segment of optical fiber that forms the laser source of the transducer, and having such a device incorporated into the actuator in order to compensate, by modifying the length of the segment of fiber, for the variations in wavelength induced in the laser by the variations in temperature.

A continuous optical beat laser element for generating terahertz (THz) waves and a laser source using same includes periodically poled lithium niobate (ppLN) crystals arranged along a predetermined direction forming a surface generally parallel to the predetermined direction. A Ti diffused region is applied on the surface and an array of gold nanowires are applied on the Ti diffused region to form a gold metal-insulator-metal (MIM) element that optimizes coupling and channeling of THz radiation from the crystals into the gold nanowires. The system provides a simple, stable, compact and cost-effective THz source using a widely tunable C-band SOA-based laser to excite a non-linear photo-mixer to produce terahertz radiation that ranges from 0.8 to 2.51 THz at room temperature. This laser source can be modified into an all fiber-based THz generator by embedding ppLN crystals in a fiber filament configuration resulting in less absorption and producing high output power.

A micro femtosecond laser with reduced radiation and temperature sensitivity is provided. The laser includes a housing with a radiation shield. Optical components that include a micro gain element are received within the housing. An input end of a pump light delivering fiber is positioned outside the housing. An output end of the pump light delivering fiber is positioned within the housing to deliver input beams to the optical components. A light signal generating pump is used to generate the input beams that are communicated to the input end of the pump light delivering fiber. A first end of a hollow core fiber is positioned within the housing to be in optical communication with the optical components. A second end of the hollow core fiber is positioned outside the housing. A partially reflective output coupling mirror is in optical communication with the second end of the hollow core fiber.

An interferometric distance measurement device includes a multiple wavelength light source, supplying a light beam having at least three different wavelengths. An interferometer unit is provided, which splits the light beam into a measuring light beam and a reference light beam. The measuring and reference light beams reflected back by measuring and reference reflectors are superimposed in an interfering manner to form an interference light beam. The interference light beam is split via a detection unit such that, in each instance, a plurality of phase-shifted, partial interference signals result per wavelength. With the aid of a signal processing unit, an absolute position information item regarding the measuring reflector is determined from the partial interference signals of different wavelengths.

A method for operating a laser device, including providing a laser pulse in a resonator so that the laser pulse circulates in the resonator, the laser pulse having a carrier wave; determining an offset frequency (f.sub.0) of the frequency comb corresponding to the laser pulse, the frequency comb having a plurality of laser modes (f.sub.m) at a distance (f.sub.rep) from one another, the frequencies of which can be described by the formula: f.sub.m=m*f.sub.rep+f.sub.0, m being a natural number, and varying the offset frequency (f.sub.0) by varying a geometric phase () that is imparted to the carrier wave of the laser pulse per resonator circulation.

In an example, a mode-locked laser includes a resonator cavity having a saturable absorber, a hollow core fiber coupled to the saturable absorber, and an optical amplifier optically coupled between the hollow core fiber and an output coupler. The mode-locked laser further includes a first pump laser and a wavelength division multiplexer coupled to the first pump laser. The wavelength division multiplexer is configured to couple light from the first pump laser into the resonator cavity to pump the optical amplifier. The mode-locked laser is configured to generate a pulse waveform at a repetition rate of approximately 100 MHz to 200 MHz.

A method of making a porous three-dimensional object. The method comprises: a) positioning a first layer of particles on a build plate; b) heating the first layer of particles sufficiently to fuse the particles together to form a first build layer having a first porosity; c) exposing the first build layer to a laser beam to form one or more pores, the exposed first build layer having a first modified porosity, the laser beam being emitted from an optical fiber; d) adjusting one or more beam characteristics of the laser beam prior to or during the exposing of the first build layer, the adjusting of the laser beam occurring prior to the laser beam being emitted from the optical fiber; e) positioning an additional layer of particles on the exposed first build layer; f) heating the additional layer of particles sufficiently to fuse the particles together to form a second build layer having a second porosity; g) exposing the second build layer to the laser beam to form one or more pores, the exposed second build layer having a second modified porosity, the laser beam being emitted from the optical fiber; h) adjusting one or more beam characteristics of the laser beam after fusing the particles to form the second build layer and prior to or during the exposing of the second build layer, the adjusting of the laser beam occurring prior to the laser beam being emitted from the optical fiber, and i) repeating e), f), optionally g) and optionally h) to form a three-dimensional object.