Downloading Thorlabs OSA 2.75 from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. This free program was originally developed by Thorlabs. The program's installer is commonly called Thorlabs OSA.exe.
The program is included in System Utilities. The following versions: 2.7 and 2.0 are the most frequently downloaded ones by the program users. We cannot guarantee that the program is safe to download as it will be downloaded from the developer's website. Before launching the program, check it with any free antivirus software.
From the developer:
Thorlabs OSA is a tool for the Optical Spectrum Analyzer and CCD Spectrometers. The software download page also offers programming reference notes for interfacing with the Optical Spectrum Analyzers using LabVIEW, Visual C++, Visual C#, and Visual Basic.
You may want to check out more software, such as Thorlabs Kinesis, Thorlabs Instrument Communicator or OSA Kit Pro Player, which might be related to Thorlabs OSA.