Abstract: A display device may include a projector coupled to volume Bragg grating (VBG) based pupil-replicating lightguide. The projector may be a scanning projector or a display panel based projector. A lighting unit for the display panel may have spatially variant spectral composition selected to match angular and wavelength selectivity of the VBGs of the pupil-replicating lightguide, thereby improving light utilization efficiency of the display device. In scanning projector implementations, the center wavelength of the scanned light beam may be varied in coordination with the scanning, to achieve the same effect.

Abstract: A display device may include a projector coupled to volume Bragg grating (VBG) based pupil-replicating lightguide. The projector may be a scanning projector or a display panel based projector. A lighting unit for the display panel may have spatially variant spectral composition selected to match angular and wavelength selectivity of the VBGs of the pupil-replicating lightguide, thereby improving light utilization efficiency of the display device. In scanning projector implementations, the center wavelength of the scanned light beam may be varied in coordination with the scanning, to achieve the same effect.

Abstract: A display device includes an optical assembly and a display that includes a front surface and a back surface. The display is configured to output image light from the front surface and transmit ambient light from the back surface to the front surface. The optical assembly includes a substrate that has a substantially uniform thickness, a beam splitter, and a reflector. The optical assembly is configured to receive the image light output from the front surface of the display and to transmit a portion of the image light at a first non-zero optical power via an optical path that includes reflections at the reflector and at the beam splitter. The optical assembly is also configured to transmit a portion of the ambient light through the optical assembly at a second optical power without reflection at the reflector. The second optical power is less than the first optical power.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, one or more additional n-contacts are formed within the LED array. In some embodiments, the n-contacts may replace a pixel of the LED array. In other embodiments, one or more p-contacts of the LED array are resized or repositioned to accommodate the additional n-contacts without sacrificing pixels of the LED array.

Abstract: Disclosed herein are techniques for forming a thin-film circuit layer on an array of light-emitting diodes (LEDs). LEDs in the array of LEDs can be singulated by various processes, such as etching and ion implantation. Singulating LEDs can be performed before or after forming the thin-film circuit layer on the array of LEDs. The array of LEDs can be bonded to a transparent or non-transparent substrate.

Abstract: A color converter device includes an array of color conversion regions. The array of color conversion regions includes color conversion regions of a first type and color conversion regions of a second type that is distinct from the color conversion regions of the first type. A respective color conversion region of the array of color conversion regions includes a respective photonic crystal structure defining a respective two-dimensional pattern. The respective color conversion region includes a respective color conversion matrix. The color conversion regions of the first type converts light of a first color into light of a second color that is distinct from the first color and the color conversion regions of the second type converts the light of the first color into light of a third color that is distinct from the first color and the second color.

Abstract: For small, high-resolution, light-emitting diode (LED) displays, such as for a near-eye display in an artificial-reality headset, LEDs are spaced closely together. A backplane can be used to drive an array of LEDs in an LED display. A plurality of interconnects electrically couple the backplane with the array of LEDs. The backplane can have a different coefficient of thermal expansion (CTE) than the array of LEDs. During bonding of the backplane to the array of LEDs, CTE mismatch can cause misalignment of bonding sites. The higher the bonding temperature, the greater the misalignment of bonding sites. Lower temperature bonding, using materials with lower melting or bonding temperatures, can be used to mitigate misalignment during bonding so that interconnects can be more closely spaced, which can allow LEDs to be more closely spaced, to enable a higher-resolution display.

Abstract: Disclosed herein are techniques for forming a thin-film circuit layer on an array of light-emitting diodes (LEDs). LEDs in the array of LEDs can be singulated by various processes, such as etching and ion implantation. Singulating LEDs can be performed before or after forming the thin-film circuit layer on the array of LEDs. The array of LEDs can be bonded to a transparent or non-transparent substrate.

Abstract: Disclosed herein are techniques for forming a thin-film circuit layer on an array of light-emitting diodes (LEDs). LEDs in the array of LEDs can be singulated by various processes, such as etching and ion implantation. Singulating LEDs can be performed before or after forming the thin-film circuit layer on the array of LEDs. The array of LEDs can be bonded to a transparent or non-transparent substrate.

Abstract: For small, high-resolution, light-emitting diode (LED) displays, such as for a near-eye display in an artificial-reality headset, LEDs are spaced closely together. A backplane can be used to drive an array of LEDs in an LED display. A plurality of interconnects electrically couple the backplane with the array of LEDs. The backplane can have a different coefficient of thermal expansion (CTE) than the array of LEDs. During bonding of the backplane to the array of LEDs, CTE mismatch can cause misalignment of bonding sites. The higher the bonding temperature, the greater the misalignment of bonding sites. Lower temperature bonding, using materials with lower melting or bonding temperatures, can be used to mitigate misalignment during bonding so that interconnects can be more closely spaced, which can allow LEDs to be more closely spaced, to enable a higher-resolution display.

Abstract: A display device including a laser-based light engine is disclosed. Optical interference effects due to the coherent nature of a laser light source are mitigated by shortening a coherence length of the laser source. The coherence length shortening is achieved by at least one of the following: providing a multiple longitudinal mode laser source, pulsing a laser source to achieve spectral broadening, or providing multi-emitter laser source(s) with emission wavelength varying from emitter to emitter.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, a current spreading layer having a conductive material (e.g., a conductive oxide) is formed on a surface of the substrate of the LED assembly. The current spreading layer may be a bulk layer or be patterned to increase light extraction from the LEDs of the array.

Abstract: For small, high-resolution, light-emitting diode (LED) displays, such as for a near-eye display in an artificial-reality headset, LEDs are spaced closely together. A backplane can be used to drive an array of LEDs in an LED display. A plurality of interconnects electrically couple the backplane with the array of LEDs. As spacing between LEDs becomes smaller than interconnect spacing, a thin-film circuit layer can be used to reduce a number or interconnects between the backplane and the array of LEDs, so that interconnect spacing can be larger than LED spacing. This can allow LEDs in the LED display to be more densely arranged while still allowing use of a silicon backplane with drive circuitry to control operation of the LEDs in the LED display.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, one or more additional n-contacts are formed within the LED array. In some embodiments, the n-contacts may replace a pixel of the LED array. In other embodiments, one or more p-contacts of the LED array are resized or repositioned to accommodate the additional n-contacts without sacrificing pixels of the LED array.

Abstract: A display device including a laser-based light engine is disclosed. Optical interference effects due to the coherent nature of a laser light source are mitigated by shortening a coherence length of the laser source. The coherence length shortening is achieved by at least one of the following: providing a multiple longitudinal mode laser source, pulsing a laser source to achieve spectral broadening, or providing multi-emitter laser source(s) with emission wavelength varying from emitter to emitter.

Abstract: In a flip-chip LED assembly having an array of LEDs formed on the same substrate, different LEDs of the array have different distances to the n-contacts of the assembly. This may cause current crowding as current has to spread from the n-contacts through the substrate to each the farthest LEDs of the LED array, requiring LEDs that are farther away to be driven with a higher voltage in order to receive a desired amount of current. To spread current more evenly through the LED assembly and reduce a voltage difference between the closest and farthest LEDs of the array, a current spreading layer having a conductive material (e.g., a conductive oxide) is formed on a surface of the substrate of the LED assembly. The current spreading layer may be a bulk layer or be patterned to increase light extraction from the LEDs of the array.

Abstract: A display device includes an optical assembly and a display that includes a front surface and a back surface. The display is configured to output image light from the front surface and transmit ambient light from the back surface to the front surface. The optical assembly includes a substrate that has a substantially uniform thickness, a beam splitter, and a reflector. The optical assembly is configured to receive the image light output from the front surface of the display and to transmit a portion of the image light at a first non-zero optical power via an optical path that includes reflections at the reflector and at the beam splitter. The optical assembly is also configured to transmit a portion of the ambient light through the optical assembly at a second optical power without reflection at the reflector. The second optical power is less than the first optical power.

Abstract: Disclosed herein are techniques for forming a thin-film circuit layer on an array of light-emitting diodes (LEDs). LEDs in the array of LEDs can be singulated by various processes, such as etching and ion implantation. Singulating LEDs can be performed before or after forming the thin-film circuit layer on the array of LEDs. The array of LEDs can be bonded to a transparent or non-transparent substrate.

Abstract: Embodiments relate to forming nanoporous contacts on a receiving substrate without using a seed layer on the receiving substrate. The nanoporous contacts can be used to create bonds between electronic components and the receiving substrate. To form the contacts, a photoresist mask is created on the receiving substrate by a photolithographic process. Through a sputtering process, portions of co-alloy on a depositing substrate are transferred to the receiving substrate with the photoresist mask. The photoresist mask is removed from the receiving substrate. The remaining co-alloy portions on the receiving substrate undergo a de-alloying process to form an array of nanoporous contacts.

Abstract: A display device includes a light source device, and a color converter optically coupled with the light source device. An array of regions of the light source device is configured to emit light of a first color. The color converter includes an array of color conversion regions including color conversion regions of a first type and of a second type. The color conversion regions of the first type are configured to convert the light of the first color into light of a second color. The color conversion regions of the second type are configured to convert the light of the first color into light of a third. A respective color conversion region of the array of color conversion regions includes a respective photonic crystal structure defining a respective two-dimensional pattern including one or more induced defects, and a color conversion matrix that includes color converting nanoparticles.