Posts

2nd IFU prototype nearly spot-on!

May 30, 2024

2nd IFU prototype nearly spot-on! # After the promising performance of the 3D printed IFU prototype in early 2023, we moved forward with a 2nd IFU prototype. Some design adjustments were made to ease the work of Keynote Photonics and make the 2nd IFU even better. We mostly reduced the pitch to 125 microns, so that fibers are now in contact. We cannot do less, unless using more exotic fibers. ...

Starting of the test of the thermal enclosure after its completion

March 15, 2024

15-03-2024 # Starting of the test of the thermal enclosure after its completion # We have completed the thermal enclosure. It will be tested, with the vacuum tank, but without the optics and optomechanical assembly. It will be tested outside our building to be is conditions as close as possible to the telescope dome environment.

PIAA-Prototype Manufacture

November 6, 2023

06-11-2023 # PIAA prototype Manufacture # We have ordered a PIAA optics, made of CaF2. It is being manufactured in a single piece, by diamond turning. Overall wavefront error seems very promizing. It will be tested on a nulling test bench that is under construction.

Spectrograph Tank Delivery

September 21, 2023

21-09-2023 # Spectrograph Tank Delivery # The spectrograph manufacturing is in course. Today we received the Vacuum tank. It looks pretty “RISTRETTO” compared to its predecessors. We immediately pumped it to check vacuum tightness: After some trial and error the pressure reached 1.5 10-5 mBar

Nulling experiments with 3d printed IFU

June 30, 2023

30-06-2023 # Nulling experiments with 3d printed IFU # The IFU has been put to te test. First cheching its properties, and then we could test the coupling properties and the nulling with our ring coronagraph. A lot has been learned, and we are devloping a new test bench for improving upon the test that have been performed.

Starting the tests of the WFS camera

April 1, 2023

01-04-2023 # Starting the tests of the WFS camera # We have identified that the WFS camera must be the CRED-One from First Light Instrument and we got the funding to buy one. We received it and we are now starting to characterize it.

Spectrograph Design Review

December 20, 2022

20-12-2022 # Spectrograph Design Review # We had a successful spectrograph Design review. In order to validate the spectrograph hardware design and start fabrication. We also presented the status of the design of the Front end. Thanks to all the reviewer!

PIAA Coronagraph

June 29, 2022

29-06-2022 # PIAA Coronagraph # A new Coronagraph has been studied for RISTRETTO and shows very promizing characteristics. It is a PIAA, based coronagraph, that using distortion change the illumination of the pupil of the instrument from a top-hat (minus obstruction and spiders) to a truncated gaussian. The gaussian profile allow to increase significantly the coupling into the fibers for the planetary signal, the truncation allow for the nulling of the stellar signals. ...

3d printed IFU prototype

January 1, 2022

01-01-2022 # 3d printed IFU prototype # We have manufactured a an IFU prototype, using 3d printing technology. It was one of the few available solution to achieve the extremely tight requirement we have in the relative alignment of the micolenses to the fibers. The procurement has been done in 2 steps : The manufacture of a bundle of 7 fibres assembled in an hexagonal pattern The printing on top of the bundle, with the possibility to center as well as possible each micro lens to the actual fiber core position. ...