Low Level Optical Detection using Lock-in Amplifier Techniques

ثبت نشده
چکیده

This note describes a number of techniques that can be used to detect low level optical signals. It starts by considering the problems inherent in the use of DC techniques and how these may be reduced by using AC methods instead. It then discusses a range of different experimental approaches using lock-in amplifiers, pointing out the advantages as well as any disadvantages of each method. Finally, it outlines the important specifications of the mechanical light choppers that are often used as part of such systems.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

A Simple Microcontroller Based Digital Lock-in Amplifier for the Detection of Low Level Optical Signals

Traditionally digital lock-in amplifiers sample the input signal at a rate much higher than the lock-in reference frequency and perform the lock-in algorithm with high-speed processors. We present a small and simple digital lock-in amplifier that uses a 20 bit current integrating analogue-to-digital converter interfaced to a microcontroller. The sample rate is set to twice the reference frequen...

متن کامل

Compact low-cost detection electronics for optical coherence imaging.

A compact and low-cost detection electronics scheme for optical coherence imaging is demonstrated. The performance of the designed electronics is analyzed in comparison to a commercial lock-in amplifier of equal bandwidth. Images of a fresh-onion sample are presented for each detection configuration.

متن کامل

Theory and Applications of Frequency Domain Laser Ultrasonics

In frequency domain laser ultrasonics, the pulsed laser source used for ultrasound excitation in conventional laser ultrasonics is replaced by a low power, amplitude modulated laser source. The acoustic signals are detected using an interferometer or contact transducer, coupled to a RF lock-in amplifier or vector network analyzer. The detection bandwidth reduction afforded by this technique all...

متن کامل

Polarization modulation in optoelectronic generation and detection of terahertz beams

Compared with the conventional laser amplitude modulation with a lock-in amplifier, the optical polarization modulation in optoelectronic generation and detection of a free-space terahertz ~THz! radiation provides up to twofold increase of the dynamic range. The total laser power for the optoelectronic generation of THz beams can be fully utilized. © 1999 American Institute of Physics. @S0003-6...

متن کامل

A quasilinear wide-range radiometer amplifier implemented with correlated phase-sensitive detection

A radiometer amplifier capable of wide-range optical measurement is described. Based on a novel automatically ranged electrometer and amplifier circuit, the radiometer provides a quasilinear analog output for the measurement of input radiation over ten orders of magnitude. Together with the scheme of phase-sensitive detection of modulated optical signals, the circuit resulted in an output volta...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2000