Abstract: An optical modulator includes a photonic substrate a first modulator arm disposed on the photonic substrate. The first modulator arm is configured to modulate a first optical signal portion of an input optical signal at a first signal level. The optical modulator further includes a second modulator arm disposed on the photonic substrate. The second modulator arm is configured to modulate a second optical signal portion of the input optical signal at a second signal level that is different from the first signal level. The optical modulator further includes an optical combiner configured combine the first optical signal portion at the first signal level and the second optical signal portion at the second signal level to impart a target chirp onto the recombined optical signal. The target chirp is based on a signal level difference between the first signal level and the second signal level.

Abstract: A photonic integrated circuit (PIC) includes photonic components fabricated on the PIC. One of the photonic components includes an optical coupler configured to optically couple to an optical component. The optical coupler includes waveguide elements arranged in a 2-Dimensional array that is configured to provide a first mode having a first shape chosen to match a second shape of a second mode of the optical component.

Abstract: A method for forming a silicon optical modulator with improved modulation efficiency. the method includes providing a silicon layer in a SOI substrate and forming a waveguide in the silicon layer with a rib structure respectively joining with a first slab region on one side and a second slab region on opposite side with corresponding slab thicknesses smaller than the rib structure. The method additionally includes forming multiple etched sections in each of the first slab region and the second slab regions with decreasing etching depths for sections further away from the rib structure. Furthermore, the method includes forming a PN junction in the rib structure with a moderate P/N doping level. Moreover, the method includes doping the multiple etched sections in the first/second slab region respectively with P-type/N-type impurity at increasing doping levels sequentially for sections further away from the rib structure.

Abstract: A method for forming a silicon optical modulator with improved modulation efficiency. the method includes providing a silicon layer in a SOI substrate and forming a waveguide in the silicon layer with a rib structure respectively joining with a first slab region on one side and a second slab region on opposite side with corresponding slab thicknesses smaller than the rib structure. The method additionally includes forming multiple etched sections in each of the first slab region and the second slab regions with decreasing etching depths for sections further away from the rib structure. Furthermore, the method includes forming a PN junction in the rib structure with a moderate P/N doping level. Moreover, the method includes doping the multiple etched sections in the first/second slab region respectively with P-type/N-type impurity at increasing doping levels sequentially for sections further away from the rib structure.

Abstract: A silicon optical modulator with improved bandwidth includes a silicon waveguide with a rib structure in cross section connected to a first slab region and a second slab region respectively on two opposite sides of the rib structure. The silicon optical modulator further includes a PN junction formed in the rib structure with a P-type part joined with the first slab region and a N-type part joined with the second slab region. Additionally, the silicon optical modulator includes multiple P-type doped sections formed one next to another in the first slab region ended with a first end region and multiple N-type doped sections one next to another formed in the second slab region ended with a second end region. The multiple P-type or N-type doped sections are configured with increasing doping levels for sections further away from the rib structure.

Abstract: A surface grating coupler for polarization splitting or diverse includes a planar layer and an array of scattering elements arranged in the planar layer at intersections of a first set of concentric elliptical curves crossing with a second set of concentric elliptical curves rotated proximately 90 or 180 degrees to form a two-dimensional (2D) grating. Additionally, the grating coupler includes a first waveguide in double-taper shape and a second waveguide in double-taper shape respectively for split or diverse an incident light into the 2D grating into two output light to two output ports with a same (either TE or TM) polarization mode or one output port with TE polarization mode and another output port with TM polarization mode. The polarization diverse grating coupler is required to test multiple polarization sensitive photonics components and can be used with other single polarization grating coupler via a fiber array to perform wafer-level testing.

Abstract: The present disclosure provides an optical equalizer for photonics system in an electric-optical communication network. The optical equalizer includes an input port and an output port. Additionally, the optical equalizer includes a filter having a number of stages coupled to each other in a multi-stage series with an output terminal of any stage being coupled to an input terminal of an adjacent next stage while the input terminal of a first stage of the multi-stage series being coupled from the input port. Each stage includes a tap terminal configured to pass an optical power factored by a coefficient of multiplication from the corresponding input terminal of the stage to a tap-output path characterized by a corresponding phase delay. Furthermore, the optical equalizer includes a combiner configured to sum up the optical powers respectively from the number of tap-output paths of the multi-stage series to the output port.

Abstract: A surface grating coupler for polarization splitting or diverse includes a planar layer and an array of scattering elements arranged in the planar layer at intersections of a first set of concentric elliptical curves crossing with a second set of concentric elliptical curves rotated proximately 90 or 180 degrees to form a two-dimensional (2D) grating. Additionally, the grating coupler includes a first waveguide in double-taper shape and a second waveguide in double-taper shape respectively for split or diverse an incident light into the 2D grating into two output light to two output ports with a same (either TE or TM) polarization mode or one output port with TE polarization mode and another output port with TM polarization mode. The polarization diverse grating coupler is required to test multiple polarization sensitive photonics components and can be used with other single polarization grating coupler via a fiber array to perform wafer-level testing.

Abstract: A surface grating coupler for polarization splitting or diverse includes a planar layer and an array of scattering elements arranged in the planar layer at intersections of a first set of concentric elliptical curves crossing with a second set of concentric elliptical curves rotated proximately 90 or 180 degrees to form a two-dimensional (2D) grating. Additionally, the grating coupler includes a first waveguide in double-taper shape and a second waveguide in double-taper shape respectively for split or diverse an incident light into the 2D grating into two output light to two output ports with a same (either TE or TM) polarization mode or one output port with TE polarization mode and another output port with TM polarization mode. The polarization diverse grating coupler is required to test multiple polarization sensitive photonics components and can be used with other single polarization grating coupler via a fiber array to perform wafer-level testing.

Abstract: The present disclosure provides an optical equalizer for photonics system in an electric-optical communication network. The optical equalizer includes an input port and an output port. Additionally, the optical equalizer includes a filter having a number of stages coupled to each other in a multi-stage series with an output terminal of any stage being coupled to an input terminal of an adjacent next stage while the input terminal of a first stage of the multi-stage series being coupled from the input port. Each stage includes a tap terminal configured to pass an optical power factored by a coefficient of multiplication from the corresponding input terminal of the stage to a tap-output path characterized by a corresponding phase delay. Furthermore, the optical equalizer includes a combiner configured to sum up the optical powers respectively from the number of tap-output paths of the multi-stage series to the output port.

Abstract: The present disclosure provides an optical equalizer for photonics system in an electric-optical communication network. The optical equalizer includes an input port and an output port. Additionally, the optical equalizer includes a filter having a number of stages coupled to each other in a multi-stage series with an output terminal of any stage being coupled to an input terminal of an adjacent next stage while the input terminal of a first stage of the multi-stage series being coupled from the input port. Each stage includes a tap terminal configured to pass an optical power factored by a coefficient of multiplication from the corresponding input terminal of the stage to a tap-output path characterized by a corresponding phase delay. Furthermore, the optical equalizer includes a combiner configured to sum up the optical powers respectively from the number of tap-output paths of the multi-stage series to the output port.