Chapter 3 Overview; Parts List - THORLABS SA201-EC Operating Manual

Spectrum Analyzer Controller

Chapter 3 Overview

Thorlabs' Scanning Fabry-Perot (FP) Interferometers are spectrum analyzers that
are ideal for examining fine spectral characteristics of CW lasers. The controller
generates a voltage ramp, which is used to scan the separation between the two
cavity mirrors. The controller provides adjustment of the ramp voltage and scan
time, allowing the user to choose the scan range and speed. An offset control is
provided to allow the spectrum displayed on the oscilloscope to be shifted right or
left. Another convenient feature of the controller is a zoom capability that provides
a 1X, 2X, 5X, 10X, 20X, 50X and 100X increase in the spectral display resolution.
The output TTL level trigger allows the user to externally trigger an oscilloscope
on either the beginning or midpoint of the ramp waveform.
The SA201 also includes a high precision photodetector amplifier circuit used to
monitor the transmission of the cavity. The amplifier provides an adjustable
transimpedance gain of 10,000, 100,000, and 1,000,000 V/A when driving a high
impedance load, such as an oscilloscope. Using the output sync signal from the
controller, an oscilloscope can be used to display the spectrum of the input laser.
The detector circuitry incorporates a blanking circuit, which disables the
photodiode response during the falling edge of the saw tooth waveform.
3.1.

Parts List

Below is a list of all components shipped with the SA201 Spectrum Analyzer
Controller.
•
SA201 Spectrum Analyzer Controller
•
Operating Manual
•
120 VAC US Power Supply Line Cord (with the SA201) or 230 VAC
Power Supply Line Cord for Europe (with the SA201-EC)
•
125 mA Fuse for use at 230 VAC operation (250 mA fuse installed in unit)
Rev H, November 30, 2021
Chapter 3: Overview
Page 3