An optical system is configured to support eye tracking operations in a head mounted device. The optical system includes a transparent layer, a laser, and first and second output couplers. The laser is configured to emit light into the transparent layer. The first output coupler is configured to out-couple a first portion of the light from a first location of the transparent layer. The second output coupler is configured to out-couple a second portion of the light from a second location of the transparent layer. The first and second output couplers are in the field-of-view of a user. A combination of the first portion of the light and the second portion of the light out-coupled from the first output coupler and the second output coupler is configured to generate a fringe pattern, for example, on an eye of a user of the head mounted device.

An electrically controlled depolarizer based on a crossed-slit waveguide (3) includes a horizontal-slit waveguide (1), a 45-degree polarization rotation waveguide (2), a pair of modulation electrodes (4) and the crossed-slit waveguide (3). Broad-spectrum TM (transverse magnetic) polarized light is inputted from one end of the horizontal-slit waveguide (1), and then a part of the broad-spectrum TM polarized light is converted into broad-spectrum TE (transverse electric) polarized light through the 45-degree polarization rotation waveguide (2), and then the broad-spectrum TE polarized light and the remaining broad-spectrum TM polarized light enter an input end of the crossed-slit waveguide (3); the board-spectrum TE polarized light is transmitted in a vertical slit of the crossed-slit waveguide (3); the remaining broad-spectrum TM polarized light is transmitted in a horizontal slit of the crossed-slit waveguide (3); and the broad-spectrum TE polarized light and the remaining broad-spectrum TM polarized light form depolarized light at an output end of the crossed-slit waveguide (3). The pair of modulation electrodes (4) realize the precise adjustment of the rotation angle of the 45-degree polarization rotation waveguide (2) by electronic control, such that the TE polarized light and the TM polarized light at the output end of the crossed-slit waveguide (3) have equal energy, thereby overcoming uneven light splitting caused by loss of the polarization rotation waveguide and TE and TM waveguide transmission loss.

An optical device is described. At least a portion of the optical device includes ferroelectric non-linear optical material(s) and is fabricated utilizing ultraviolet lithography. In some aspects the at least the portion of the optical device is fabricated using deep ultraviolet lithography. In some aspects, the short range root mean square surface roughness of a sidewall of the at least the portion of the optical device is less than ten nanometers. In some aspects, the at least the portion of the optical device has a loss of not more than 2 dB/cm.

An optical device includes a substrate, a layered structure provided on the substrate and including an intermediate layer, an optical waveguide formed of a thin crystal film having an electro-optic effect, and a buffer layer stacked in this order, and an electrode provided on or above the buffer layer and configured to apply a direct current voltage to the optical waveguide. The resistivity of the intermediate layer is higher than the resistivity of the buffer layer.

A method of integrating an optoelectronic device comprising a Pockels material, such as lithium niobate (LiNbO3), includes forming an optoelectronic device layer over a semiconductor layer. The optoelectronic device layer includes a patterned optoelectronic device segment in an interlayer dielectric. A window is etched in the interlayer dielectric using the patterned optoelectronic device segment as a sacrificial etch stop. The patterned optoelectronic device segment is removed in the window. The optoelectronic device comprising the Pockels material is formed in place of the removed patterned optoelectronic device segment. The optoelectronic device comprising the Pockels material may be formed from an optoelectronic chiplet.

In an optical waveguide element, an optical waveguide is formed on a substrate, the optical waveguide has a main waveguide that propagates signal light, a waveguide for unnecessary light that guides unnecessary light released from the main waveguide, and a waveguide for collecting unnecessary light to which the unnecessary light emitted from the waveguide for unnecessary light is introduced, the waveguide for unnecessary light is connected to the waveguide for collecting unnecessary light via a waveguide for connection, and a width of the waveguide for connection, which is a width in a direction that perpendicularly intersects a propagation direction of the unnecessary light, at a portion connected to the waveguide for collecting unnecessary light is set to be wider than a width at a portion connected to the waveguide for unnecessary light with the waveguide for connection.

An optical element includes an optical waveguide layer. The optical waveguide includes a periodic structure of grooves. The optical waveguide layer has a layer-thickness equal to or greater than 1.5 m and is made of material selected from a group consisting of Ta2O5, Al2O3, LiNbO3, LiTaO3, AlN, GaN, SiC, and Yttrium aluminum garnet (YAG). (D/0.5)2.5 is satisfied where D indicates the depth of groove; and indicates the pitch of the arranged grooves in the periodic structure. The unit of is identical to the unit of D.

A hybrid photonic chip comprising a plurality of semiconductor materials arranged to define a chip providing a function, wherein at least a first part of the chip is formed of materials which can be fabricated using a CMOS technique; and at least a second part of the chip which comprises non-linear crystal material and is not subjected to etching process; wherein the second part of the chip in conjunction with the first part is configured to support a propagating low loss single mode.

An optical device comprises a photonic integrated circuit having an optical mode coupler. The optical mode coupler optically couples a first planar optical waveguide having a first optical core at one horizontal plane to a second planar optical waveguide having a second optical core at a different second horizontal plane. The optical mode coupler comprises two or more intermediate optical layers stacked vertically between the horizontal planes of the optical cores, and intermediate optical layer comprises one or more optical rails. The optical mode coupler causes light received from the first planar optical waveguide to excite an optical mode and guide the light of the optical mode such that the optical mode substantially overlaps the first planar optical waveguide and the optical rails of at least two of the intermediate optical layers in a vertical cross-section of the photonic integrated circuit.

The present disclosure provides an embodiment of a photonics structure that includes a ring optical waveguide on a substrate; a rail optical waveguide configured to couple a light into the ring optical waveguide; and enhancement features configured around the ring optical waveguide and the rail optical waveguide to enhancement the photonic structure.