JFET Buffering Input and Bootstrap Structure

We design a low-noise, large-dynamic-range amplifier based on transimpedance amplifier (TIA) for detecting shot noise of 1064-nm laser in quantum optical experiments. Compared with a single-junction field-effect transistor (JFET) buffered TIA, the electronic noise is effectively 2.8 dB suppressed at the analysis of 2 MHz, and 4 dB suppressed at 4 MHz by means of a JFET bootstrap structure. Under the transimpedance gain of 200 k$Omega $ and 0.5 pF.

The measured shot noise at the injected laser power of$51~mu $ W is 12.5 dB above the electronic noise at 2 MHz, and 9.8 dB at 4 MHz. With adjustment of bias condition of the bootstrap structure and application of a $L$ – $C$ (inductance and capacitance) structure, the dynamic range is largely boosted from the original 1.52 to 11.22 mW. The amplifier meets the requirement of SNR for Bell-state detection in quantum optical experiments.