Fig. 2: A prototype of the packaged device.
From: 120 GOPS Photonic tensor core in thin-film lithium niobate for inference and in situ training
a Photo of the entire device. The top is our hybrid integrated chip; the Bottom is the electric control and power supply circuits of the charge-integration photoreceiver. b is a micrograph of our hybrid integrated chip, including the fabricated TFLN photonic circuit, flip-chip photodetectors, and laser. c–e is the zoomed-in micrographs of flip-chip photodetectors (PDs), the traveling-wave electrode of the modulator, and the laser, respectively. f A micrograph of the side view of our device, showing the relative heights of the TFLN chip, laser, and photodetectors. g The light-current-voltage curves for the light coupled into the TFLN chip from the laser. h Electro-optic bandwidth (S21 parameter) of the modulator. i The output voltage of the photoreceiver varies with the integration time when the input optical power is fixed at a certain value. In a balanced detection scheme, when the optical power received by PD1 is lower than that received by PD2, the output voltage variation of the integrator is positive, and, when it is higher than that received by PD2, the output voltage variation of the integrator is negative.
