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.

An optical assembly reduces a spectral bandwidth of an output beam of a laser. The assembly includes a beam-expanding optical unit within a laser resonator. The latter serves to increase a beam cross section of a resonator-internal laser beam in at least one expansion cross-sectional dimension such that at least one resonator-internal expansion laser beam section arises. The assembly also includes an optical grating in a retroreflective arrangement for the resonator-internal laser beam. A beam-limiting stop acts in the expansion cross-sectional dimension and is arranged in the beam path of the expansion laser beam section. This yields an optical assembly in which unwanted thermal effects on account of optical components of the optical assembly heating during laser operation due to a local power density of the resonator-internal laser beam are reduced or avoided.

A line narrowing module includes a prism that refracts laser light in a first plane, a grating that disperses the laser light in the first plane, first to fourth elements, and a rotation mechanism and narrows the linewidth of the laser light. The second element is supported between the first and fourth elements by the first element. The rotation mechanism rotates the second element relative to the first element around an axis intersecting the first plane. The prism is located between the second and fourth elements and so supported by the second element that the rotation mechanism rotates the prism and the second element. The third element has elasticity and is compressed and located between the prism and the fourth element. The fourth element receives reaction force from the compressed third element. The second element is mechanically independent of the fourth element in the rotational direction of the rotation mechanism.

An apparatus including an external cavity laser with an optical cavity, the optical cavity bounded by optical reflectors. The optical cavity can include an optical gain module capable of amplifying light, a tunable endless optical phase shifter and a wavelength-tunable optical filter. The apparatus can also include an electronic control module connected to enable adjustment of a phase shift accumulated by the light propagating through the tunable endless optical phase shifter and connected to enable adjustment of a passband wavelength of the wavelength tunable optical filter. Another apparatus as described above with no wavelength-tunable optical filter present.

An apparatus including an external cavity laser with an optical cavity, the optical cavity bounded by optical reflectors. The optical cavity can include an optical gain module capable of amplifying light, a tunable endless optical phase shifter and a wavelength-tunable optical filter. The apparatus can also include an electronic control module connected to enable adjustment of a phase shift accumulated by the light propagating through the tunable endless optical phase shifter and connected to enable adjustment of a passband wavelength of the wavelength tunable optical filter. Another apparatus as described above with no wavelength-tunable optical filter present.

A laser device for laser resonance ionization includes a wavelength variable grating-type titanium-doped sapphire laser and includes a titanium (Ti) doped titanium sapphire crystal disposed within a resonator. The titanium sapphire crystal is fixedly disposed on a stage. The titanium-doped sapphire crystal can be moved in the optical axis direction by the stage, thereby changing the position of the titanium-doped sapphire crystal. The switching between the wideband mode and the high-output mode can be performed by changing the position of the titanium-doped sapphire crystal.

A laser device for laser resonance ionization includes a wavelength variable grating-type titanium-doped sapphire laser and includes a titanium (Ti) doped titanium sapphire crystal disposed within a resonator. The titanium sapphire crystal is fixedly disposed on a stage. The titanium-doped sapphire crystal can be moved in the optical axis direction by the stage, thereby changing the position of the titanium-doped sapphire crystal. The switching between the wideband mode and the high-output mode can be performed by changing the position of the titanium-doped sapphire crystal.

A fiber laser producing a beam of ultrashort laser pulses at a repetition rate greater than 200 MHz includes a linear fiber resonator and a fiber branch. Ultrashort laser pulses are generated by passive mode-locking and circulate within the linear fiber resonator. Each circulating laser pulse is split into a portion that continues propagating in the linear fiber resonator and a complementary portion that propagates through the fiber branch and is then returned to the linear fiber resonator. The optical length of the linear fiber resonator is an integer multiple of the optical length of the fiber branch. The repetition rate of the ultrashort laser pulses is the reciprocal of the propagation time of the laser pulses through the fiber branch.

A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser.

A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser.