Optical laboratory

The Astrophysics Institute of Andalucía (IAA) has an Optics Laboratory which is part of the Instrumental and Technological Development Unit (UDIT). The Optics Lab is dedicated both to the development of astronomical instrumentation in the visible and NIR ranges and to the maintenance of the telescopes at the Sierra Nevada Observatory (OSN) with its associated instrumentation.

Activity at OSN consists in: participation in the design and integration of existing equipment, improvements, maintenance of the optical quality of the telescopes, maintenance of all the optical surfaces of the observatory (including the aluminized mirrors, cleaning them and the optical components of associated instrumentation) and the monitoring and control of the reflectivity of the mirrors of the telescopes.

The lab is also involved in the optical integration of the PANIC camera and the CARMENES-NIR spectrograph for the Calar Alto Observatory.

At the optical lab facilities, are accomplished all kinds of optical measurements: quality of optical surfaces, relative transmittance calibrations on astronomical filters, lenses, optical fibres for use in astronomy and so on; emissivity calibrations on spectral lamps, continuous lights or any other type of lamp (LEDs, light pollution...); detector calibrations in visible and infrared (CCDs, photomultipliers, NIR detectors...); alignment and integration of instruments; testing of prototypes and any other kind of optical tasks.

A good laboratory is justified for regular and systematic calibration of the IAA teams' equipment in order to ensure the optimization of optical and mechanical characteristics of highly sophisticated and high price equipment.

The major equipment available today are:

  • A Twyman-Green interferometer by Fisba Optik with a 100mm collimated laser beam of 632nm.
  • A Varian/Agilent UV-VIS-NIR spectrophotometer Cary 5000 with an operating range between 175-3300 nm.
  • A wavefront sensor HASO3 32 by Imagine Optic, adapted to the Nasmyth foci of the 1.5m and 0.9m telescopes in the OSN, with an extended calibration range between 500nm and 900nm.
  • A IRIS908RS reflectometer which measures both reflectance (at 470nm, 530nm, 650nm and 880nm) and scattering (at 670nm), at different angles for flat or slightly curved surfaces.
  • A Jarrel-Ash monochromator of 0.5m focal length, with different gratings to optimally cover the range from 300nm to NIR.
  • A radiometer by UDT Instruments, Model S370, with two probes, one made of silicon and another made of germanium, covering the range between 300nm and 1.8μm.
  • A pyroelectric radiometer by Laser Precision, model RS-5900 with large spectral range.
  • A secondary standard Black Body.
  • An optical table to mount experiments and a basic set of mounts and light sources.
  • The laboratory is equipped with specific instrumentation and a wide variety of general purpose components such as lenses, optical systems, lasers, optical and infrared detectors, filters, light sources, spectral lamps, etc..
  • A He-Ne laser for alignment.
  • A semi-automatic data acquisition software, ADLO (Optics Laboratory Data Acquisition), controlled by a PC.

The Optics Laboratory rooms are on the ground floor of the UDIT building in order to make it as insensitive as possible to all kinds of vibrations. These vibrations are highly undesirable because they greatly affect the positioning and alignment of the equipment, which is so critical in any optical assembly. There are two rooms.

Optics laboratory

This lab is inside an improved 100,000 class clean room, with temperature and humidity control. It is also built without windows to minimize the entry of radiation, both visible and infrared, which can introduce unwanted noise in the calibrations and experiments. All activities requiring controlled cleanliness, temperature, humidity and darkness. In this room is also kept instrumentation and optical components that require these special conditions.

The access to this laboratory is through a pre-clean room containing the mandatory clothing for all personnel who enter the lab.  

AIV optical room

This room is a 100,000 class clean room used for assembly, integration and verification of the optical components to be mounted on the instruments developed at the IAA. It has a cold water supply and the access is made through a pre-clean room as well.