Provided are a saturable absorber including at least one material selected from a group of MXenes, and a Q-switching and mode-locked pulsed laser system using the same.

The invention provides a lighting device configured to generate lighting device light, wherein the lighting device light includes an emission band in the visible part of the spectrum which represents at least 80% of the total power (W) of the lighting device light in the visible part of the spectrum, wherein the emission band has a full width half maximum of at maximum 60 nm, and wherein the emission band has a peak maximum (MM3), wherein said emission band includes luminescent material light, wherein the lighting device includes (i) a solid state-based light source, configured to generate light source light having a peak maximum (MX2), and (ii) a luminescent material, configured to convert at least part of the light source light into said luminescent material light, wherein the solid state-based light source is configured to provide said light source light with 0<MM3MX2<60 nm.

An optical system comprising a charged quantum dot having, a charged carrier, first and second ground state levels and a plurality of excited state levels, the first and second ground state energy levels having different spin states such that the said charged carrier cannot transfer between the first and second ground state energy levels without changing its spin state, the system further comprising a controller adapted to control a first radiating beam with energy not more than 100 micro-eV from a first transition within said quantum dot from a first ground state level to a selected excited state level from the plurality of excited state levels to, the system being adapted to enhance the decay rate of a second transition within said quantum dot from the selected excited state level to a second ground state level, but not a first transition, such that a photon is produced due to scattering of a photon from the first radiating beam, wherein the controller is adapted to irradiate the quantum dot with the first radiating beam for a time longer than the radiative lifetime of the selected excited state to produce just one photon, and wherein the first radiating beam comprises at least one pulse.

An optical system comprising a charged quantum dot having, a charged carrier, first and second ground state levels and a plurality of excited state levels, the first and second ground state energy levels having different spin states such that the said charged carrier cannot transfer between the first and second ground state energy levels without changing its spin state, the system further comprising a controller adapted to control a first radiating beam with energy not more than 100 micro-eV from a first transition within said quantum dot from a first ground state level to a selected excited state level from the plurality of excited state levels to, the system being adapted to enhance the decay rate of a second transition within said quantum dot from the selected excited state level to a second ground state level, but not a first transition, such that a photon is produced due to scattering of a photon from the first radiating beam, wherein the controller is adapted to irradiate the quantum dot with the first radiating beam for a time longer than the radiative lifetime of the selected excited state to produce just one photon, and wherein the first radiating beam comprises at least one pulse.

The invention provides a lighting device (100) configured to generate lighting device light (101), wherein the lighting device light (101) includes an emission band (110) in the visible part of the spectrum which represents at least 80% of the total power (W) of the lighting device light (101) in the visible part of the spectrum, wherein the emission band (110) has a full width half maximum of at maximum 60 nm, and wherein the emission band (110) has a peak maximum (MM3), wherein said emission band (110) comprises luminescent material light (21), wherein the lighting device (100) comprises (i) a solid state-based light source (10), configured to generate light source light (11) having a peak maximum (MX2), and (ii) a luminescent material (20), configured to convert at least part of the light source light (11) into said luminescent material light (21), wherein the solid state-based light source (10) is configured to provide said light source light (11) with 0<MM3MX2<60 nm.

Provided are a saturable absorber including at least one material selected from a group of MXenes, and a Q-switching and mode-locked pulsed laser system using the same.

One-dimensional nanostructures having uniform diameters of less than approximately 200 nm. These inventive nanostructures, which we refer to as nanowires, include single-crystalline homostructures as well as heterostructures of at least two single-crystalline materials having different chemical compositions. Because single-crystalline materials are used to form the heterostructure, the resultant heterostructure will be single-crystalline as well. The nanowire heterostructures are generally based on a semiconducting wire wherein the doping and composition are controlled in either the longitudinal or radial directions, or in both directions, to yield a wire that comprises different materials. Examples of resulting nanowire heterostructures include a longitudinal heterostructure nanowire (LOHN) and a coaxial heterostructure nanowire (COHN).