Group Laboratories
Raman Lab
The Raman Laboratory has a Jobin Yvon T64000 triple spectrometer, with macro and
microscope entraces, plus an additional entrance to the spectrometer via a notch filter.
With three grating sets and two entrance set ups we are able
to perform optical studies between 250 and 1500 nm. Two different detectors are available,
an open electrode CCD for the UV and visible range and an InGaAs diode array for the
near infrared. A motorized table allows automatic mappings, line scannings or signal
variations in depth. A galvanometric linescanning can provide the complete spectra of
a line by using the second dimension of the CCD, i.e. a collection of 512 spectra can be
taken at the time. A micro-cryostat from Cryovac allows the low-temperature measurements
at the Raman system.
Four lasers supply different monochromatic wavelengths to the Raman Lab
or any other system by means of optical fibers. The Spectrum 70 is a laser with a
Kr and Ar mixture which provides several wavelengths in the visible range from the violet
to the red. The SABRE is an Argon laser with 30 W of total power (6 W in the UV). In the visible it supplies
the typical lines of the Argon. This laser has a deep UV line at 275 nm. We have also a 325 nm laser from Soliton and a FRED laser supplying 244 nm. Most of the
laser lines are filtered with interferometer filters, but we also have an UV and a visible
prism monochromator at the exit of the lasers to eliminates the plasma lines. We have a 532 nm laser (Verdi-12 W) and a Ti-Dye and Ti-Sapphire ring laser for
variable wavelengths measurements.
Optical constants
In this laboratory we can carry on optical measurements (transmission, reflectance,
photoluminescence and, recently, also Raman) in the optical range from 180 to 2500 nm. The set up consists
of a simple spectrometer from McPherson with three high luminosity gratings, spectral lamps (deuterium,
mercury or halogen) and different detectors (ANDOR EM-CCD, UV enhanced, a nitrogen cooled
InGaAs detector, a micro-channel plate and other single detectors for both UV and VIS) to
cover the mentioned spectral range. The micro-channel plate is controlled with a Pico-Harp 300 system. A closed-cycle cryostat allows us to perform measurements
between 6 and 300 K. A high temperature cell allows to extend the range of optical or
photo-transport measurements to 1500 degrees Celsius.
Magneto-optics
The magnetic field lab is equipped with a 14 T magnet from Cryogenic Ltd.,
with an optical access. The temperature in the sample cryostat ranges from 2 to 300 K.
For transport measurements we use a switching system and a software program written in labview. The electrical measurements can be performed as a function of temperature
or magnetic field automatically. For magnetooptics we either use a simple spectrometer (triax 180) or bring the signal to the other lab with a McPherson spectrometer and an ANDOR CCD.
[<]
Back
MAIN PAGE
