Lock-in amplifier Definition and 17 Threads

I'm setting up an EPR (Electron Paramagnetic Resonance) instrument and encountering an issue with the lock-in amplifier. I’d like to share the details of the problem and receive any help or advice. First, I’ll briefly explain the setup. (See Figure 1) On the left side of Figure 1, you can see...

Hello everyone, I am using a lock-in amplifier SR860 with the aim of reading an optical pulse from a laser break-out board operating at 30 kHz as the reference. The reference signal is not being picked up by the lock-in amplifier. However, it is being read by the oscilloscope. I have used a...

Hi, I am trying to use the SR865A lock-in amplifier to measure the frequency of a pulse of a sine wave( example: waveform below), - the sinewave signal is only ON during finite time not continuously-, I am using an external reference signal that is also a pulse of a sinewave with the same...

Hello, I'm using a lock in amplifier (model 5210 from signal recovery) for some experiments with photodiodes. Firstly, there is an optical chopper that "feeds" the lock in (reference signal). My input is a photodiode (in current mode). The problem is,the unlock (unlk) light is always on in the...

Hello I am currently have difficulties trying to measure dc-modulated voltages while applying a dc current, via Sr830 Lock-in Amplifier (LIA). Basically, I apply an 2 GHz ac current (amplitude modulated@10kHz and referenced to the LIA for lock-in measurement) and a dc current to my DUT...

Dear Physics Forums, For a research we are conducting, we're seeking some input from users of a Lock-in Amplifier. If you use a Lock-in Amplifier, could you provide me with a few answers to the following questions? What's your overall experience with lock-in amplifiers? Have you encountered...

Hello. I am currently modifying a semiconductor experiment. A laser beam is modulated with an acousto-optical modulator and illuminate the semiconductor sample. The sample is probed by microwaves. The reflected microwave signal go through a demodulator, and then in a lock-in amplifier. Then I...

Hi guys~ I have a question about lock-in detection method that commonly used in optical spectroscopy experiments, for example, the optical pump-probe reflectivity exeperiments on some semiconductor surfaces, or kinda like that. Usually, the sinario is: you use laser pulses, divided as pump and...

I just started to use a lock-in amplifier, and I am trying to following the procedures by adjusting zero phase. But my input phase changes with time and sensitivity, and I couldn't lock in onto it. The question is, is this normal that phase changes all the time during the experiment or if there...

Hey I have a quick question whose answer is well-hidden on google since the key word of the search attempts is sensitivity, which of course returns results about phase-sensitive detection, and seemingly phase-sensitive detection only... My question is what the exact definition of the...

Hello everyone I have completed my freshman year in EE. For the summer, my professor has asked me to design a lock-in amplifier. First he has asked me to read about AD630. Now after reading the datasheet at (http://www.analog.com/static/imported-files/data_sheets/AD630.pdf), I was a bit...

I have a project where I'm measuring the phase of a signal compared to a signal reference using an SR830 lock-in amplifier. My problem is that the amplitude of the input signal periodically changes over time and this is causing a false measurement in the phase of the input signal. I can't figure...

Hi Usually when a lock-in amplifier is introduced to students, it is done when the input signal is a harmonic function and the reference is one as well. This is a nice concept, and it is easy to see how a DC-term propotional to the (desired) incident amplitude can be obtained. My question...

What is a "lock-in amplifier with a forcing grid"? The context of the title is in an undergrad paper, concerning plasma waves in an glow discharge column. The paragraph which mentioned this is in the section of the paper, Suggestions for Further Research: The most important step remaining...

I have two current signals from a two color Si-photodiode/PbS-photodetector. I want to measure the signal with the Stanford Research Lock-In Amplifier 830. I read in the manual that I can measure currents with the SR830. Does anyone have experience with this? Do I get better signals if I...

Dear all, I measured some very nice data, but it's difficult to analyze, but I try to get out of it what I can. I have diverging resistance and did measure with standard lock-teqnique: apply 0.45V over preresistor and send current over sample and measure the two-probe resistance over the same...

Hi to all, For a project I need to measure output (as Volts) of a circuit. I want to do this with a SRS830 lock-in by using Labview application. Google search gave me nothing. If anyone knows how to set this up, please help. Thanks