Patent ID: 11899060
Assignee: BATTELLE MEMORIAL INSTITUTE
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 10:
11. An optical carrier injection device comprising:
a laser driven by a radio frequency (RF) signal configured to apply a pulsed optical beam having pulse duration of 900 femtoseconds or lower on a backside of a substrate of an integrated circuit (IC) wafer or chip;
an optical train arranged to focus the pulsed optical beam at a focal point in an active layer disposed on a frontside of the substrate; and
a readout device configured to measure an output signal comprising an electrical signal produced by the IC wafer or chip in response to the carriers injected at the focal point in the active layer or a light output signal produced by recombination of the carriers injected at the focal point or nonlinear interactions in the active layer;
wherein the readout device uses lock-in amplification and includes a lock-in amplifier that is locked to a reference signal comprising boxcar averaging triggered from laser pulses of the pulsed optical beam;
wherein a photon energy of the pulsed optical beam is lower than a bandgap of the substrate; and
wherein photons of the optical beam are absorbed at the focal point in the active layer by nonlinear optical interaction to inject carriers at the focal point in the active layer.