A thermal radiation light source includes a laminated body including m quantum layers laminated where m is an integer of 2 or more, including an n-layer and a p-layer sandwiching the quantum layers from both sides in the laminating direction, the n-layer made of an n-type semiconductor and the p-layer made of a p-type semiconductor; a voltage applying unit for the m quantum layers is directly or indirectly connected to the n-layer and p-layer sandwiching each layer applying a voltage for moving to the n-layers or p-layers a charge; a voltage switching unit switches ON/OFF of application of the voltage to the m quantum layers; and a photonic crystal portion disposed in the laminated body or adjacent to the laminated body, so that lights of m wavelengths resonate, the lights of the m wavelengths generated in the m quantum layers corresponding to transition energy between subbands in the quantum layer.

A photonic crystal device includes a two-dimensional crystal including a gain medium and having a first photonic crystal resonator and a second photonic crystal resonator spaced apart from each other and a graphene layer disposed to cover a portion of the first photonic crystal resonator and not to cover the second photonic crystal resonator.

Structures for response shaping in frequency and time domain, include an optical response shaper and/or a modulator device with multiple injection. The device comprises a resonator having an enclosed geometric structure, for example a ring or racetrack structure, at least two injecting optical waveguides approaching the resonator to define at least two coupling regions between the resonator and the injecting waveguides, and may define at least two Free Spectral Range states.

One or both of the coupling regions has a coupling coefficient selected for a predetermined frequency or time response, and the coupling coefficient or other device parameters may be variable, in some case in real time to render the response programmably variable.

Provided are light sensing systems and electronic apparatuses including the light sensing systems. The light sensing system includes a light source unit having a slit-shaped opening and configured to emit light through a slit-shaped opening; and a lens integrated with the light source unit on a surface of the light source unit on which the slit-shaped opening is formed. The lens is configured to make light emitted through the slit-shaped opening into a point light source at a far-field.

Optical systems can emit train(s) of light pulses onto objects to derive a distance between the light source and the object. Achieving meter or centimeter resolution may require very short light pulses. It is not trivial to design a circuit that can generate narrow current pulses for driving a diode that emits the light pulses. An improved driver circuit has a pre-charge path comprising one or more inductive elements and a fire path comprising the diode. Switches in the driver circuit are controlled with predefined states during different intervals to pre-charge current in the one or more inductive elements prior to flowing current through the fire path to pulse the diode.

A tunable optical source includes a substrate, a light source disposed on the substrate, and a wavelength selecting element configured to select light of a specific wavelength as output light, from light emitted from the light source, in accordance with a control signal. On the substrate, a wavelength filter including multiple output ports and a photodetector are disposed. The wavelength filter is configured to receive a part of the output light and to output light beams to the respective output ports. The photodetector is configured to receive the light beam output from one of the output ports. The tunable optical source further includes an inspection waveguide connecting to the photodetector at one end, and an inspection light input unit for inputting inspection light provided at the other end of the inspection waveguide.

A pixel structure for a vertical cavity surface emitting laser has an emission window. The pixel structure includes a plurality of sub-pixels in the emission window. Bright-area sub-pixels emit light and dark-area sub-pixels having no light emission. The bright-area sub-pixels and the dark-area sub-pixels are arranged in a pattern in the emission window. Various patterns are possible. Different structures for implementing the sub-pixels are described.

A pixel structure for a vertical cavity surface emitting laser has an emission window. The pixel structure includes a plurality of sub-pixels in the emission window. Bright-area sub-pixels emit light and dark-area sub-pixels having no light emission. The bright-area sub-pixels and the dark-area sub-pixels are arranged in a pattern in the emission window. Various patterns are possible. Different structures for implementing the sub-pixels are described.

Provided are light sensing systems and electronic apparatuses including the light sensing systems. The light sensing system includes a light source unit having a slit-shaped opening and configured to emit light through a slit-shaped opening; and a lens integrated with the light source unit on a surface of the light source unit on which the slit-shaped opening is formed. The lens is configured to make light emitted through the slit-shaped opening into a point light source at a far-field.

A lighting circuit comprises a current driver circuit and a series connection of at least two laser diodes, supplied with current from the current driver circuit. A current shunt circuit is in parallel with each laser diode for diverting a shunt current away from the respective laser diode. The level of the shunt currents is controlled during a start-up period of time of the current driver circuit in order to control the rate of change of voltage across selected laser diodes during said start-up period of time.