The LIDA-SRS-KIT Lock-In Digital Amplifier system provides an effective and user-friendly method for measuring optical signals. The system includes Oriel’s TracQ™ Basic software that acquires spectroscopic measurement data quickly and easily, without requiring any programming knowledge. The chopper included with the system is used to modulate a continuous wave source for detectors – a requirement when using a lock-in digital amplifier.

What makes up the LIDA system?

Lock-In Digital Amplifier

The Lock-In Digital Amplifier, when used with an optical chopper, removes background signals through phase sensitive detection. This technique extracts very small signals obscured by noise sources many times larger by locking into the specific modulation frequency of the desired signal. 

The Lock-In Digital Amplifier provides high performance at a reasonable cost. Features include:

Software

TracQ™ Basic allows users to acquire spectroscopic measurement data quickly and easily, without requiring any programming knowledge. TracQ™ Basic is an application integrating Oriel monochromators with the SR810 Lock In Digital Amplifier. The detection system may also be used to perform a time interval scan on a light source, such as a laser.

Software prompts guide users through the measurement process. Instruments are controlled and scan parameters are set up through simple, intuitive dialog boxes. The front panel of the software allows one to see instrument status, present wavelength, signal reading and the selected wavelength units. 

TracQ™ Basic is true radiometry software, which enables users to acquire basic voltage measurements or use the built-in algorithms for spectroscopic measurements. Data acquisition and processing occurs in real time. The following types of scans may be performed:

Loading the wavelength spectral responsivity information provided with a calibrated detector into the software also allows optical power measurements to be made.

Optical Chopper

The Model 75160NF Optical Chopper is used to introduce a periodic interruption of a light path in an optical experiment resulting in an amplitude modulation, which is useful for many small optical signal detection schemes. The modulation frequency can be controlled from 4 Hz to 2.0 kHz. Full control is available through the Optical Chopper Controller’s front panel. In addition, the Chopper Controller can be programmed over a USB communication interface to set and measure the modulation frequency, adjust the interruption phase, and perform all other operations available through the front panel.

A multi-aperture wheel installed into an enclosed chopper head is driven at a user-specified frequency by a sophisticated controller unit. The Oriel optical chopper system includes the chopper controller, chopper head with interface cable, four wheels, software, LabVIEW examples and more. Chopper wheels are easily interchangeable. The four interchangeable chopper wheels included with the system operate at user-selectable frequencies of 4 Hz to 2.0 kHz. 

The chopping frequency selection allows the experimental conditions to be optimized according to the needs of the application. The optimal frequency can be set for the experiment based on the sensitivity of the specific type of detector being utilized. A higher chopping frequency allows the system to follow faster changing signals. If necessary, a specific frequency selection removes power line generated noise from the system. The lock-in digital amplifier acts as a frequency driver for the chopper controller. The frequency is easily set through the TracQ Basic software.

The enclosure is designed with standard Oriel 1.5-inch series flanges, allowing it to be mounted directly to a wide variety of instruments and accessories. The enclosed design allows high chopping rates to be utilized in a safe manner while improving performance. The enclosed chopper head design prevents detector saturation from unchopped background light and prevents scattering. The enclosure of the wheel also reduces noise and enhances safety.

Detector Options

A broad selection of detectors are compatible with this system, allowing measurement of optical radiation from UV to IR. Each LIDA detector includes an integrated amplifier. All models except pyroelectric include a selectable gain switch. The LIDA detectors include all cables necessary to perform measurements. Thermoelectrically cooled detectors include a cable that connects to the77055 Cooler Controller. A special cable is included with each LIDA detector, providing power from the SR810 to the integrated detector amplifiers.

Silicon Detectors

Germanium Detectors

Pyroelectric Detectors

Lead Sulfide Detector

Other Detectors

The LIDA system also supports other detectors and Photomultiplier Tubes (PMTs), both amplified and unamplified, with a BNC output connector. The 70710 Preamplifier, when used with an unamplified detector, converts the signal from current to voltage. This option allows users to take advantage of the LIDA system’s greater dynamic range for voltage readings.

Legacy Products

The LIDA-SRS-KIT replaces Oriel\'s legacy Merlin lock-in digital amplifier models 70100, 70102, 70103, 70104 and 70105.

Many of Oriel\'s legacy amplified detectors may easily be integrated with the LIDA, provided the detector has Mini-DIN and BNC connectors. Discard the Mini-DIN connector included with the legacy detector and replace it with cable model <REF=279745> to provide power to the built-in preamplifier. Add a BNC cable, such as the model <REF=279747>, to send the signal output from the detector to the LIDA.

The following is a list of Oriel legacy amplified detectors which may be replaced by a similar LIDA detector.

Germanium: 70336, 70340, 70359, 70360, 71618, 7167, 71628
PbS: 70323, 70343
Pyroelectric: 70362, 70363
Silicon: 70331, 70333, 70336NS, 70338, 70351, 70353NS, 70356, 70358, 71884, 71885, 71890, 71891