Subscribe free to our newsletters via your
. 24/7 Space News .

Dichroic Beamsplitter Directs Telescope Stargazing
by Staff Writers
La Palma, Chile (SPX) Feb 12, 2013

File image: Gran Telescopio de Canarias.

Optical Surfaces has manufactured and supplied a 180mm diameter dichroic beamsplitter that will form a key component of the adaptive optics currently being integrated with the Gran Telescopio de Canarias (GTC).

The Gran Telescopio de Canarias is a 10.4m reflecting telescope with a segmented primary mirror. It is located at the Roque de los Muchachos Observatory on the island of La Palma, one of the top astronomical sites in the northern hemisphere. The GTC ( is a Spanish initiative lead by the Instituto de Astrofisica de Canarias.

Mireia Rosado Rubio, an Optical Engineer in the Development Group at the Gran Telescopio de Canarias commented "The adaptive optics (AO) system is intended to provide diffraction limited images with the GTC in the H and K bands. This is achieved by correcting the wavefront distortions induced by atmospheric turbulence. A Shack-Hartmann type wavefront sensor measures the perturbations, and a corrective element (deformable mirror) applies the opposite of the perturbations measured in order to cancel the wavefront distortions.

The dichroic beamsplitter is an essential component of the GTC AO system, as it allows us to direct the infrared part of the spectrum to the science instrument and the visible part of the spectrum to the wavefront sensor. In this way, all the light in the part of the spectrum we are interested in, is delivered to the science instrument".

She added " We selected Optical Surfaces Ltd to supply the dichroic beamsplitter because of its considerable expertise and experience in producing demanding high precision optics and optical systems, at an affordable price, for terrestrial telescope and satellite based space observation systems ". "The dichroic beamsplitter supplied fulfilled all our requirements and we were particularly pleased with the support provided by Optical Surfaces after delivery".

Dr Aris Kouris of Optical Surfaces Ltd commented "A key objective in the production of the Infrasil 301 dichroic beamsplitter was to maintain a good surface accuracy for the filter side and a good wavefront error in transmission at the exit of the filtering window. One of the major difficulties we had to overcome, in order to do this, was to maintain the surface accuracy at the filter side since hard AR coatings tend to pull the surface and add power.

In order to maintain a low contribution of saggita error we deliberately left one side slightly concave and the other slightly convex. The reason for this is because we know that hard coatings tend to convert surfaces into becoming more convex after they have been coated.

The coating that was considered to exert the strongest pull was applied to the concave side whereas the coating considered to have the least stronger pull was applied at the convex side.

The idea was that after coating the differential between the two coatings would tend to make the concave side more convex and the convex side more concave and act as a compensating factor at the correct direction. The effective result would be to have a flatter surface at both sides and or minimise the effects of power error contribution after coating".


Related Links
Optical Surfaces
Space Telescope News and Technology at

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

2012: The Webb Telescope's Big Year of Progress
Greenbelt MD (SPX) Feb 07, 2013
The James Webb Space Telescope marked another year of significant progress in 2012 as flight instrumentation was completed and delivered to NASA. The year brought forth the delivery of two types of flight mirrors, the Mid-Infrared Instrument (MIRI), the Fine Guidance Sensor and Near-Infrared Imager and Slitless Spectrograph (FGS/NIRISS), and the completion of the center section of the prim ... read more

Building a lunar base with 3D printing

US, Europe team up for moon fly-by

Russia to Launch Lunar Mission in 2015

US, Europe team up for moon fly-by

In milestone, Mars rover collects first bedrock sample

How The World's Saltiest Pond Gets Its Salt; Implications For Water On Mars

Lockheed Martin Completes Assembly, Begins Environmental Testing of NASA's MAVEN Spacecraft

NASA Curiosity Rover Collects First Martian Bedrock Sample

Supersonic skydiver even faster than thought

Ahmadinejad says ready to be Iran's first spaceman

Iran's Bio-Capsule Comes Back from Space

A Hero For Humankind: Yuri Gagarin's Spaceflight

Reshuffle for Tiangong

China to launch 20 spacecrafts in 2013

Mr Xi in Space

China plans manned space launch in 2013: state media

Progress docks with ISS

NASA to Send Inflatable Pod to International Space Station

ISS to get inflatable module

ESA workhorse to power NASA's Orion spacecraft

Ariane 5 delivers record payload off back-to-back launches this week

Eutelsat and Arianespace sign new multi-year multiple launch services agreement

Ariane 5 Arrives At Kourou For 4th Automated Transfer Vehicle Mission

Rocketdyne Powers Atlas 5 Upper Stage, Placing New Landsat In Orbit

Earth-like planets are right next door

Direct Infrared Image Of An Arm In Disk Demonstrates Transition To Planet Formation

Kepler Data Suggest Earth-size Planets May Be Next Door

Earth-like planets may be closer than thought: study

3D Printing on the Micrometer Scale

Nextdoor renovates before taking on the world

High-energy X-rays shine light on mystery of Picasso's paints

Satellite undergoes extreme testing

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement