Apparatus is provided including an acoustic sensor (50) having an optical waveguide (20). The optical waveguide (20) includes a waveguide core (202) having a waveguide core refractive index and a waveguide core photo-elastic coefficient, and an over-cladding layer (204) coupled to the waveguide core (202) and including an optically transparent polymer having an over-cladding refractive index and an over-cladding photo-elastic coefficient. The waveguide core refractive index is greater than the over-cladding refractive index, and the over-cladding photo-elastic coefficient is greater than the waveguide core photo-elastic coefficient. Other applications are also described.

Apparatus is provided including an acoustic sensor (50) having an optical waveguide (20). The optical waveguide (20) includes a waveguide core (202) having a waveguide core refractive index and a waveguide core photo-elastic coefficient, and an over-cladding layer (204) coupled to the waveguide core (202) and including an optically transparent polymer having an over-cladding refractive index and an over-cladding photo-elastic coefficient. The waveguide core refractive index is greater than the over-cladding refractive index, and the over-cladding photo-elastic coefficient is greater than the waveguide core photo-elastic coefficient. Other applications are also described.

A display device including: a first substrate; first through third subpixel electrodes which are disposed on the first substrate to neighbor each other; a second substrate opposing the first substrate; a first wavelength conversion pattern at least partially overlapping the first subpixel electrode and a second wavelength conversion pattern at least partially overlapping the second subpixel electrode; a first light transmission pattern at least partially overlapping the third subpixel electrode and a second light transmission pattern disposed between the first wavelength conversion pattern and the second wavelength conversion pattern; and a low refractive layer which has a lower refractive index than the first and second wavelength conversion patterns.

A display device including: a first substrate; first through third subpixel electrodes which are disposed on the first substrate to neighbor each other; a second substrate opposing the first substrate; a first wavelength conversion pattern at least partially overlapping the first subpixel electrode and a second wavelength conversion pattern at least partially overlapping the second subpixel electrode; a first light transmission pattern at least partially overlapping the third subpixel electrode and a second light transmission pattern disposed between the first wavelength conversion pattern and the second wavelength conversion pattern; and a low refractive layer which has a lower refractive index than the first and second wavelength conversion patterns.

Disclosed is a three-dimensional imaging system. The system comprises: an optical emitter that emits light pulses to a target scene; an optical modulator that modulates the optical state of at least part of the light pulses emitted from the optical emitter and/or of at least part of light pulses returned from the target scene; an optical element array that receives a modulated light pulses; a photoelectric detector that comprises an imaging lens, and receives an optical signal passing through the optical element array and converts the received optical signal into an electrical signal; and a controller, wherein the controller applies a control to the optical modulator by means of a circuit, the optical modulator modulates the optical state of the light pulses into a function of time on the basis of the control.

Acoustically mediated pulsed radiation sources, phased arrays incorporating the radiation sources, and methods of using the radiation sources and phased arrays to generate electromagnetic radiation via magnetic dipole emission are provided. The radiation sources are based on a superlattice heterostructure that supports in-phase magnetic dipole emission from a series of magnetic insulator layers disposed along the length of the heterostructure.

Acoustically mediated pulsed radiation sources, phased arrays incorporating the radiation sources, and methods of using the radiation sources and phased arrays to generate electromagnetic radiation via magnetic dipole emission are provided. The radiation sources are based on a superlattice heterostructure that supports in-phase magnetic dipole emission from a series of magnetic insulator layers disposed along the length of the heterostructure.

Images of samples that are illuminated with polarized light are captured. Azimuth and inclination data are extracted from the captured images. The azimuth and inclination data are used to quantify MTRs.

A method for driving an acousto-optic element with an acousto-optic crystal and a piezoelectric transducer for setting the acousto-optic crystal in mechanical vibration includes driving the piezoelectric transducer with a drive signal with at least one drive frequency. The at least one drive frequency in alternation takes on a plurality of different values around a center frequency during a passage of a mechanical vibrational wave through the acousto-optic crystal, such that a grating that is produced owing to density fluctuations in the acousto-optic crystal exhibits different grating spacings at the same time.

A method for driving an acousto-optic element with an acousto-optic crystal and a piezoelectric transducer for setting the acousto-optic crystal in mechanical vibration includes driving the piezoelectric transducer with a drive signal with at least one drive frequency. The at least one drive frequency in alternation takes on a plurality of different values around a center frequency during a passage of a mechanical vibrational wave through the acousto-optic crystal, such that a grating that is produced owing to density fluctuations in the acousto-optic crystal exhibits different grating spacings at the same time.