摘要:
A light switch (or valve) made up of two mutually inverted, substantially identical diffraction gratings with a liquid medium therebetween, arranged to allow the grating substrates to be shifted laterally relative to one another so as to align and mis-align the grating elements. When aligned, incident-polarized light passes through the switch and when misaligned, light does not pass through the switch but is reflected.
摘要:
An acousto-optic laser beam scanner of improved scanning angle scope is provided by introducing a controllable compound acoustic waveform into a light transmissive body wherein at least binary and binary diffraction grating patterns of both positive and negative sense can be introduced into the body, the period of the waveform determining the refraction angle magnitude and the order of the pulses determining the refraction angle direction.
摘要:
A grating structure having a fused silica base includes alternating ridges and grooves. The ridges and grooves form a fused silica to air interface. The ridges and grooves are configured such that the grating has a ratio between the effective refractive index difference between s-polarization and p-polarization of about 1/3. As such, for non-polarized light with an incident angle θin of between 40° and 90° and a wavelength λ=350-1600 nm, the grating directs both s-polarization and p-polarization components of the incident light to the −1st order diffraction mode.
摘要:
A double-sided grating divider acts as a light switch where the upper and lower grating dividers are arranged to accommodate a relative lateral shift therebetween of about one-fourth of the period of the diffraction grating elements and where the critical refraction angles of the grating dividers are more than about 43.6°. Lateral shift may be achieved by various devices including MEMS and metal couplers having a known/calibrated thermal coefficient of expansion over a temperature range of interest.
摘要:
A grating structure and a solar cell assembly. In one aspect, the grating structure suppresses the zero order transmission to near 0%. In another aspect, the solar cell assembly has improved absorption due to coupling with a grating structure.
摘要:
Optical devices using double-groove diffraction gratings having periodic sets of TiO2 elements on one or more surfaces of an SiO2 substrate are disclosed. First order components of incident polarized light coupled into the substrate are reflected so as to propagate through the substrate to terminus points where they either change direction for further propagation or exit the substrate. A windshield display system using the principles of the invention is disclosed.
摘要:
A grating structure and a solar cell assembly. In one aspect, the grating structure suppresses the zero order transmission to near 0%. In another aspect, the solar cell assembly has improved absorption due to coupling with a grating structure.
摘要:
A double-sided grating divider acts as a light switch where the upper and lower grating dividers are arranged to accommodate a relative lateral shift therebetween of about one-fourth of the period of the diffraction grating elements and where the critical refraction angles of the grating dividers are more than about 43.6°. Lateral shift may be achieved by various devices including MEMS and metal couplers having a known/calibrated thermal coefficient of expansion over a temperature range of interest.
摘要:
A photonic crystal structure that is composed of a host media having periodic dielectric holes disposed in the media at a period of ah. Each dielectric hole has a radius rh. The host media has an absolute refractive index expressed as |nh| that is less than 0.2. The photonic crystal structure has at least one reflection minimization layer disposed at an air/photonic crystal interface. The reflection minimization layer has periodic dielectric holes disposed therein at a period am with each dielectric hole having a radius rm such that ah=am and rm>rn and a beam steerable device including the photonic crystal structure. The device having a scanning rate of larger than 1 KHz and a scanning angle up to ±25 degrees.
摘要:
A grating structure for splitting light. The grating structure including alternating ridges and grooves. The ridges and grooves are configured such that the grating directs p-polarization components of incident light to the −1st order diffraction mode and s-polarization components of incident light to the 0th order diffraction mode.