NFIRAOS - Adaptive Optics Subsystems for the TMT

Client: NRC Herzberg, Astronomy and Astrophysics

The Thirty Meter Telescope (TMT) is an astronomical project to build a 30-meter class optical telescope, which would eventually be one of the most powerful optical telescopes in the new generation of extremely large tele­scope.

As the TMT’s adaptive optics system, NFIRAOS is currently being developed by a group of experts in adaptive optics, including INO. The team is led by NRC Herzberg As­tronomy and Astrophysics, based in Victoria, BC.

Several challenges must be resolved for this mission to succeed. First, the mirrors in the tele­scope (and all the mechanical parts) are gigantic. The TMT’s main mirror will have a diameter of 30 meters (approximately the width of an ice hockey rink), so the subsystems are massive as well. Of course, all of the components must be of irreproachable quality. The second challenge is the temperature requirements. In order to reduce background emissivity and obtain the best possible image quality, the system must be operated at temperatures of close to –30°C, so the built subsystems must be able to function in these very harsh environmental conditions.

So far NFIRAOS was just a concept with a very long list of requirements. Now we have a detailed final design ready for fabrication. INO is turning our concept into reality!'

- Olivier Lardière, optical engineer, NFIRAOS team, NRC Herzberg

We bring our adaptive optics and optomechanical ex­pertise to the project. Our work on NFIRAOS includes four key optical subsystems that will be integrated into the telescope, namely the beamsplitters, instrument selection mirror, turbulence generator, and source simulator. 

Of the four subsystems INO is working on, two have made it past the design phase, while the other two are still at the design stage. The next step in the NFIRAOS project will be to fabricate and assemble the system. The TMT is scheduled to be up and running in 2022.

This is a good example of how Canadian organizations from coast to coast are working together and bringing complementary expertise to the table to build one of the largest optical systems ever made. With NFIRAOS as its eye, the TMT will give us a new view of the uni­verse that may provide answers about its origins.

The full paper «NFIRAOS beam splitters subsystems opto-mechanical design» is available at SPIE Digital Library.