A viewing angle controlling light source device and a display apparatus are provided. The viewing angle controlling light source device includes a base substrate; a light emitting array arranged on the base substrate, wherein the light emitting array includes a plurality of light emitting units; at least one liquid crystal lens array arranged on the light emitting array, wherein the liquid crystal lens array includes a plurality of liquid crystal lens units corresponding to the light emitting units one by one, each liquid crystal lens unit includes a first electrode and a second electrode, and a liquid crystal layer arranged between the first electrode and the second electrode, a light emergent direction of light emitted by the light emitting unit after the light transmitting through the liquid crystal lens unit by regulating a voltage difference between the first electrode and the second electrode.

A portable multispectral imaging and projecting device includes a liquid crystal light valve configured to modulate, in response to an image generated by a processor, intensity of light passing through the liquid crystal light valve. The light is emitted by a light source module and the liquid crystal valve projects the modulated light and the image to a target area. The light source module includes a plurality of visible light sources and at least one infrared light source. The image is generated in response to an infrared light image and a visible light image, or the infrared light image, wherein the images are acquired by a photoelectric sensor of an image acquiring module.

An electro-holographic light field generator device comprises surface acoustic wave (SAW) optical modulators arranged in different directions. Specifically, some embodiments have SAW modulators arranged in pairs, nose-to-nose with each other, and have output couplers that provide face-fire light emission. These SAW modulators also possibly include SAW sense transducers and/or viscoelastic surface material to reduce crosstalk.

An electro-holographic light field generator device comprises surface acoustic wave (SAW) optical modulators arranged in different directions. Specifically, some embodiments have SAW modulators arranged in pairs, nose-to-nose with each other, and have output couplers that provide face-fire light emission. These SAW modulators also possibly include SAW sense transducers and/or viscoelastic surface material to reduce crosstalk.

Electro-holographic light field generator devices comprising surface acoustic wave (SAW) optical modulators are disclosed that employ multiple output couplers. These output couplers might be distributed along waveguides of the SAW modulators, within output coupling regions. Each of these output couplers can be configured for directing an incident leaky mode light at different output angles. In some cases, it may be desirable to employ the output couplers to function as different sub-pixels, to provide light to different viewing directions. The output couplers may be mirrors, volume gratings, chirped gratings, reflection gratings, two dimensional gratings, and/or transmission gratings. The output couplers may be angled so that the coupling output fans for each optical modulator are offset from the waveguide for that optical modulator.

Aspects of the disclosed apparatuses, methods, and systems provide a wearable, augmented or virtual reality display system including two or more sets of backlight illumination arrangements. Each different set of backlight illumination is directed to a corresponding optical imaging system. The corresponding optical imaging system is designed to focus each set of illumination at a different distance. The selection of a particular optical focal distance is controlled by selecting the set of backlight illumination corresponding to the imaging system to provide the desired focal distance. As a result, selection of the backlight illumination determines at which distance an image is perceived by a user. When multiple backlight illumination sets are multiplexed with 2-D images, a single, 3-D image is perceived by the wearer of the display system.

A system includes an optical parametric oscillator (OPO) device. The OPO device has an optical resonator, a first nonlinear optical element (NLO) and a second non-linear optical element (NLO). The first NLO can produce, via OPO of a first pump beam, a first output with a first frequency and a second output with a second frequency. The second frequency is lower than the first frequency. The second NLO can produce, via OPO of a second pump beam (with a higher frequency than the first), a third output with a third frequency and a fourth output with a fourth frequency. The fourth frequency is lower than the third frequency. The first frequency is the same, or at least substantially the same, as the fourth frequency. The OPO device is configured to resonate at the first frequency and the fourth frequency.

A method is described in which a database is monitored. The database includes information specifying allocations of time periods in which a first optical carrier corresponding to a first optical channel will not be supplying encoded first data into output optical signals being transmitted from a first node to a second node. An idler carrier being amplified stimulated emission light having a frequency corresponding to the first optical channel is supplied into the output optical signals transmitted from the first node to the second node during the time periods in which the first optical carrier will not be supplying encoded first data into the output optical signals.

A method is described in which a loss of spectrum in an optical signal having an optical signal spectrum is detected. The optical signal is transmitted from a first node to a second node. In response to detecting the loss of spectrum in the optical signal, at least one idler carrier without data imposed is supplied into the optical signal spectrum transmitted from the first node to the second node, the optical signal spectrum encompassing a frequency band including a plurality of optical channels, the idler carrier being amplified stimulated emission light having a frequency corresponding to a first optical channel of the plurality of optical channels.

An optical receiver includes a cascade of optical filtering elements, each of which selects spectral components from incoming optical signals at a wavelengths aligned to filter passbands. The selected spectral components may be optically combined to form k pairs of intermediary signals, where k=log.sub.2(M). By comparing the k pairs of intermediary signals, k bits of a digital signal representing the incident signal may be generated. The filtering elements may be configured to perform demultiplexing and demodulation simultaneously, increasing functionality and reducing excess losses. The filtering elements may also be tuned so that the optical receiver may be reconfigured to accommodate different combinations of wavelengths and modulation formats, such as wavelength division multiplexed (WDM) on off keying (OOK), M-ary orthogonal formats including frequency shift keying (FSK) and pulse position modulation (PPM), differential phase shift keying, and hybrid combinationsproviding rate and format flexibility and WDM scalability.