THORLABS Redstone OSA305 User Manual

Redstone™ Optical Spectrum Analyzer Chapter 4: Description
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Figure 1. Optical Schematic of the Thorlabs Redstone OSA305
4.3. Interferogram Data Acquisition
The Redstone OSA samples the interferogram at a fixed frequency of up to 1 MHz with an 18-bit ADC while the
retroreflector platform moves at a constant speed controlled by a PID loop. The data is resampled to fit up to
128 data points per reference laser period.
A high-speed USB link transfers the interferograms to the OSA software, which is highly optimized to take full
advantage of modern multi-core processors, as well as top-performing graphics processing units (GPUs). The
software performs a number of calculations to analyze and condition the input waveform in order to obtain the
highest possible resolution and signal-to-noise ratio (SNR) at the output of the Fast Fourier transform (FFT).
Very low-noise and low-distortion detector amplifiers with automatic gain control provide a large dynamic range,
allow optimal use of the ADC, and ensure excellent SNR for up to 10 mW of input power. For low-power signals,
the system can typically detect less than 100 pW from narrowband sources for mid-wavelength models and as
low as femtowatts for short-wavelength models.
4.4. Interferogram Data Processing
The interferograms generated by the instrument vary from 50 thousand to 16 million data points depending on
the resolution and sensitivity settings employed. The OSA software analyzes the input data and intelligently
selects the optimal FFT algorithm from our internal library.
Additional software performance is realized by utilizing an asynchronous, multi-threaded approach to collecting
and handling interferogram data through the multitude of processing stages required to yield spectrum
information. The software’s multi-threaded architecture manages several operational tasks in parallel by actively
adapting to the PC’s capabilities, thus ensuring maximum processor bandwidth utilization. Furthermore, a
specialized GPU is tasked to perform the most advanced calculations. Each of our OSA instruments ships with
a laptop computer that has been carefully selected to ensure optimum data processing and user interface
operation.

THORLABS Redstone OSA305 Specifications

General

Brand	THORLABS
Model	Redstone OSA305
Category	Measuring Instruments
Language	English