Disclosed herein is a modulator (50) for polarization-division multiplexing (PDM) transmission. The modulator (50) comprises first and second DP-MZMs (12, 28) associated with first and second polarizations, each DP-MZM (12, 28) having an input for an in-phase and a quadrature driving signal for modulating the in-phase and quadrature components of an optical signal according to respective transfer functions, and a detector (58) suitable for detecting light comprising at least a portion of the light outputted by the first DP-MZM (12) and a portion of the light outputted by the second DP-MZM (28). The modulator (50) is adapted to superimpose a first pilot signal on one of the in-phase and quadrature driving signals of the first DP-MZM (12) and on one of the in-phase and quadrature driving signals of the second DP-MZM (28), and a second pilot signal on the respective other of the in-phase and quadrature driving signals of the first and second DP-MZMs (12, 28). Further, the first and second pilot signals are chosen such that the signal detected by said detector (58) is indicative as to whether the slopes of the transfer functions are different for the in-phase and quadrature components of one of the first and second DP-MZMs (12, 28) and identical for the other of the first and second DP-MZMs (12, 28).

The present disclosure provides a display substrate and a display device, belonging to the field of display technology, which can solve the problem that a splicing gap between existing adjacent display substrates of a spliced screen is relatively wide, and a narrow-bezel display cannot be realized. The display substrate of the present disclosure has a display area and a non-display area surrounding the display area; the display substrate includes a base and a plurality of pixel units located on the base and arranged in the display area; each of the pixel units includes a pixel circuit. The display substrate further includes: a light detection circuit located on the base and arranged in the non-display area; where the light detection circuit is configured to detect brightness of ambient light.

Methods and systems for encoding multi-level pulse amplitude modulated signals using integrated optoelectronics are disclosed and may include generating a multi-level, amplitude-modulated optical signal utilizing an optical modulator driven by first and second electrical input signals, where the optical modulator may configure levels in the multi-level amplitude modulated optical signal, drivers are coupled to the optical modulator; and the first and second electrical input signals may be synchronized before being communicated to the drivers. The optical modulator may include optical modulator elements coupled in series and configured into groups. The number of optical modular elements and groups may configure the number of levels in the multi-level amplitude modulated optical signal. Unit drivers may be coupled to each of the groups. The electrical input signals may be synchronized before communicating them to the unit drivers utilizing flip-flops. Phase addition may be synchronized utilizing one or more electrical delay lines.

Method for automatically protecting an object, a person, or an item of visual information from a risk of unwanted viewing by a third party, an unauthorized person and/or an image-recording device, The method includes the steps of: automatically detecting, by analyzing images from at least one lidar or from a camera arranged so as to cover a predefined surveillance area, the presence of a third party or of an unauthorized person and/or of the device in this area or nearby, the predefined surveillance area corresponding at least to an area from which the person or the device is capable of viewing the object, the person or the information, and in the event of positive detection, triggering a predefined action.

A device, includes: a ring waveguide; a diode comprising a junction extending at least partly in the ring waveguide; and a first circuit configured to supply a signal representative of a leakage current in the diode.

A display panel includes a display layer, a photosensitive layer and an infrared mask. The display layer is configured to display an image, the display layer has light-transmitting portions, and the light-transmitting portions are configured to transmit infrared light. The photosensitive layer is disposed on a side of the display layer. The infrared mask is disposed on a side of the photosensitive layer proximate to the display layer, the infrared mask has hollowed-out regions, the hollowed-out regions are configured to make the infrared mask have a preset pattern, and a region in the infrared mask except the hollowed-out regions is configured to prevent transmission of the infrared light. The photosensitive layer is configured to receive infrared light passing though the hollowed-out regions and the light-transmitting portions, and convert the infrared light into an image signal.

An electronic device is provided. The electronic device includes: a display panel including a display area in which a plurality of pixels are arranged and configured to display an image in a first direction, and a first camera module including camera circuitry and a second camera module including camera circuitry arranged under the display panel, wherein the display area includes a first display area overlapping the first camera module in the first direction and a second display area overlapping the second camera module in the first direction, wherein pixels per inch (PPI) of the first display area is less than the PPI of the second display area.

The present disclosure relates to the field of display technologies, and particularly discloses a color film substrate, a display panel, a backlight module, a display device and a display system. The color film substrate includes a plurality of pixel units arranged in an array, each of the plurality of pixel units including a first-class filtering unit and a second-class filtering unit, wherein the first-class filtering unit allows visible light to pass through and blocks invisible light, and the second-class filtering unit allows the invisible light to pass through and blocks the visible light.

A display apparatus capable of reducing a defect occurrence rate includes a display panel, a metal plate including an opening and located under the display panel to contact a lower surface of the display panel to support the display panel, and a filling layer filling the opening and including a material different from a material of the metal plate.

A tunable optical filter provides a narrow passband centered around the wavelength of the laser beam to limit ambient light noise impinging on a primary photodetector. As the wavelength changes due to temperature or other effects, the wavelength is indirectly measured and used to shift the passband of the filter to center it on the shifted wavelength. A portion of the emitted beam is diverted through the same tunable filter to a feedback photodetector. The output of the feedback photodetector will be at a maximum value when the tunable filter passband is centered on the laser beam wavelength. By controlling the passband of the tunable filter to maximize the feedback photodetector output, the passband remains centered on the laser wavelength. The tunable filter is a Liquid Crystal Tunable Filter (LCTF) or another tunable filter large enough to pass both reflected and feedback light to the primary and feedback photodetectors.