Abstract: Masing at room temperature is achieved by an apparatus and method that utilize a microwave cavity which exhibits a resonance of sufficiently high Q-factor for maser oscillation, and a resonator structure comprising a masing medium located within a resonant element. The masing medium comprises spin-defect centres. The resonator structure is disposed within the microwave cavity. A magnetic field is applied across the masing medium. An input of microwave radiation to be amplified is coupled to the resonator structure. An optical pump pumps the masing medium, thereby causing stimulated emission of microwave photons. The microwave cavity has an effective magnetic mode volume matching the volume of the masing medium.

Abstract: Masing at room temperature is achieved by an apparatus and method that utilize a microwave cavity which exhibits a resonance of sufficiently high Q-factor for maser oscillation, and a resonator structure comprising a masing medium located within a resonant element. The masing medium comprises spin-defect centres. The resonator structure is disposed within the microwave cavity. A magnetic field is applied across the masing medium. An input of microwave radiation to be amplified is coupled to the resonator structure. An optical pump pumps the masing medium, thereby causing stimulated emission of microwave photons. The microwave cavity has an effective magnetic mode volume matching the volume of the masing medium.

Abstract: There is provided a light source arranged to output light at a first wavelength. The light source comprises a luminescent concentrator having a slab-shaped geometry. The luminescent concentrator comprises: an input port arranged to receive light and define a first area; an output port arranged to transmit light and define a second area which is smaller than the first area; and surfaces arranged to direct light inside the luminescent concentrator to the output port. The luminescent concentrator further comprises lumophores arranged to receive light at a second wavelength and emit light at the first wavelength; and a pump light supply coupled to the input port and arranged to illuminate the input port with light at the second wavelength.

Abstract: There is provided a light source arranged to output light at a first wavelength. The light source comprises a luminescent concentrator having a slab-shaped geometry. The luminescent concentrator comprises: an input port arranged to receive light and define a first area; an output port arranged to transmit light and define a second area which is smaller than the first area; and surfaces arranged to direct light inside the luminescent concentrator to the output port. The luminescent concentrator further comprises lumophores arranged to receive light at a second wavelength and emit light at the first wavelength; and a pump light supply coupled to the input port and arranged to illuminate the input port with light at the second wavelength.