Single-stage photodiode op-amp solution suited for a self-mixing fmcw system

Abstract

Abstract-The current delivered by the photodiode in a self-mixing frequency modulated continuous wave or optical frequency domain reflectometry system consists of a dc-current resulting from the local oscillator, the reflected signal, dark current in the photodiode, and current generated from background light. The current also contains the useful harmonic signal with a beat frequency corresponding to the range and radial velocity of a target. To avoid saturation and clipping due to the dc current generated in the photodiode, it is desirable to minimize the gain at dc while maintaining a high gain in the beat frequency region. We have investigated some different solutions and present a modified current-to-voltage converter using bootstrapping and added voltage gain, which addresses this problem using only one OP-amp and no dc shorting inductors.Index Terms-Frequency modulated continuous wave (FMCW), operation amplifier, optical frequency domain reflectometry (OFDR), photodiode, transimpedance amplifier.

A low-cost optofluidic platform for the colorimetric assessment of bacterial activity in domestic wastewater

“…The other advantage of this circuit was that it converted the generated photocurrent into a measurable voltage. 33 Fig. 2(b) shows the linearity of the PIN-10D photodiode obtained with respect to the input optical power of an LED source.…”

“…The other advantage of this circuit was that it converted the generated photocurrent into a measurable voltage. 33 Performance comparison of the photodiode with spectrometer. The bacterial activity prole obtained using the DREAM assay was used to assess the performance of the device.…”

A Low-Noise, Large-Dynamic-Range-Enhanced Amplifier Based on JFET Buffering Input and JFET Bootstrap Structure

“…In order to amplify weak current, low noise and high input impedance enhanced TIAs are widely applied [5][6][7][8]. For the optical Bell-states (the laser power is 50 μW), the shot noise current could be estimated to be several picoamperes (pAs), [3][4][5].…”

“…However, one of critical challenges is that the input voltage noise of the op amp in the TIA would experience high-frequency noise voltage gain. So as to avoid this noise gain, it is necessary to keep the input voltage noise as small as possible, or equivalently to keep the photodiode capacitance as small as possible [3][4][5][6][7][8][9][10].…”

Analysis and Detection of Correlation photon pairs using shot noise Detection

“…The optical noise dimension at the limit sensitivity of shot noise with photo detector is a vital portion of numerous quantum optics evaluations, particularly in non-classicallight generation [1], quantum information and CV (continuous variable) quantum teleportation [2].The noise of quantum is typically measured through heterodyne detection or BHD (balanced homodyne detection), and can be usually compared with the shot-noise level of coherent light at the same power [4]. The thermal noise of resistors, dark current of the photodiode, and the noise of voltage and current in the op amps are the main providers towards electronic noise when no light is incident on the photodiode that sets a strong restriction to the quantum noise's dimension [3]. Firstly, a Trans impedance amplifier was investigated for utilize as the low-noise front-end electronics to a single photodiode-based shadow-sensor, with the shadow of the illuminated fiber falling over one vertically orientated edge of the rectangular sensor.…”