Abstract: An apparatus for providing a test signal from a device under test (DUT) to a measurement instrument is disclosed. The apparatus includes a probe head configured to receive an electrical signal from the DUT. The probe head includes an electro-optic modulator. The apparatus also includes a control box, which includes an optical source. The optical source is configured to provide an input optical signal to the electro-optic modulator, which is configured to provide an output optical signal based on the electrical signal from the DUT. The control box also includes an optical bias control circuit. Only a bias control signal is provided to the electro-optic modulator.

Abstract: An apparatus for providing a test signal from a device under test (DUT) to a measurement instrument is disclosed. The apparatus includes a probe head configured to receive an electrical signal from the DUT. The probe head includes an electro-optic modulator. The apparatus also includes a control box, which includes an optical source. The optical source is configured to provide an input optical signal to the electro-optic modulator, which is configured to provide an output optical signal based on the electrical signal from the DUT. The control box also includes an optical bias control circuit. Only a bias control signal is provided to the electro-optic modulator.

Abstract: An oscilloscope probe includes a tip network, a low-loss signal cable, and a terminating assembly. The tip network is connected to the signal cable and is configured to electrically connect to a device under test via a tip network node. The terminating assembly includes an amplifier, a feedback network and a terminating attenuator. The amplifier has an inverting input, a non-inverting input connected to ground, and an amplifier output configured to connect to an oscilloscope input. The feedback network is connected between the inverting input and the amplifier output. The terminating attenuator includes a first loop circuit and a second loop circuit. The first loop circuit is provided between the signal cable and the inverting input of the amplifier. The second loop circuit is provided between the signal cable, and ground. Resistance of terminating resistors in the loop circuits are selected to match characteristic impedance of the signal cable.

Abstract: An oscilloscope probe includes a tip network, a low-loss signal cable, and a terminating assembly. The tip network is connected to the signal cable and is configured to electrically connect to a device under test via a tip network node. The terminating assembly includes an amplifier, a feedback network and a terminating attenuator. The amplifier has an inverting input, a non-inverting input connected to ground, and an amplifier output configured to connect to an oscilloscope input. The feedback network is connected between the inverting input and the amplifier output. The terminating attenuator includes a first loop circuit and a second loop circuit. The first loop circuit is provided between the signal cable and the inverting input of the amplifier. The second loop circuit is provided between the signal cable, and ground. Resistance of terminating resistors in the loop circuits are selected to match characteristic impedance of the signal cable.