Abstract: The present disclosure relates to electro-optic modulators that include caps for optical confinement. One example embodiment includes an electro-optic modulator. The electro-optic modulator includes a first cladding layer. The electro-optic modulator also includes a second cladding layer. In addition, the electro-optic modulator includes a first waveguide. The first waveguide is at least partially encapsulated between the first cladding layer and the second cladding layer. Further, the electro-optic modulator includes a thin-film lithium niobate layer adjacent to the second cladding layer. The thin-film lithium niobate layer is on an opposite side of the second cladding layer from the first waveguide. Additionally, the electro-optic modulator includes a first cap positioned on an opposite side of the thin-film lithium niobate layer from the second cladding layer. The first cap enhances optical confinement within the thin-film lithium niobate layer.

Abstract: A superconducting circuit comprises a resonator and a Josephson junction. The resonator comprises an inductor and a capacitor. The inductor comprises a first terminal and a second terminal. The second terminal of the inductor is electrically coupled to a first terminal of the capacitor. A second terminal of the capacitor is electrically coupled to a first terminal of the Josephson junction. The terminal shared by the inductor and the capacitor is configured to be electrically coupled to an alternating current (AC) voltage source having a particular frequency and particular phase. The inductance of the inductor and the capacitance of the capacitor are selected to cause the resonator to resonate at a frequency and a phase that substantially match the particular frequency and the particular phase, respectively, of the AC voltage source to facilitate switching a state of the Josephson junction via a single flux quantum (SFQ) pulse.

Abstract: The present disclosure relates to polarization rotator-splitters that include oxide claddings. One example embodiment includes a device. The device includes a first waveguide. The first waveguide includes a first end configured to receive electromagnetic waves having a first polarization with a first mode-order and electromagnetic waves having a second polarization. The first waveguide also includes a mode-conversion section configured to convert electromagnetic waves having the second polarization into electromagnetic waves having the first polarization with a second mode-order. Additionally, the device includes a second waveguide. The second waveguide also includes a coupling section configured such that electromagnetic waves having the first polarization with the second mode-order are converted into electromagnetic waves having the first polarization with the first mode-order and coupled from the coupling section of the first waveguide into the coupling section of the second waveguide.

Abstract: A power amplifier circuitry (100) comprises: a transistor stack (110) comprising at least two stacked transistor units (112A, 112B, 112C) for amplifying input signals; wherein each stacked transistor unit (112A, 112B, 112C) comprises a plurality of controllable segments (120-1 to 120-N, 130-1 to 130-N, 140-1 to 140-N), each comprising a segment transistor (122, 132, 142), wherein source terminals (123, 133, 143) within each transistor unit are connected, drain terminals (125, 135, 145) within each transistor unit are connected and gate terminals (124, 134, 144) within each transistor unit are connected, wherein each segment transistor (122, 132, 142) further comprises a back gate terminal (126, 136, 146) for setting a body bias, wherein at least two of the segment transistors (122, 132, 142) within each transistor unit have independently connected back gate terminals (126, 136, 146); and a control unit (190) configured to control the body bias for selecting an amplifier class of each of the controllable segme