This instrument is capable of operating in three modes:
Confocal - 650 nm & white light(see below) excitation; .40,.60,.80,1.25 NA objectives; must supply own collection filters.
SNOM - 650nm & white light(see below)excitation; ~100nm aperture; must supply own collection filters
AFM - Contact mode, pulsed force mode; conducting AFM capabilities
Recently the Witec microscope has been equipped with a supercontinuum generating white light source.
This light source generates a spectrum of 400nm to 3um light by sending a high power ps pulsed 1064nm laser through a strongly dispersive photonic fiber.
The laser power of the entire integrated spectrum is 2W with about 1 mW per nm bandwidth.
The collimated broadband output of the laser is then either coupled directly into a (single mode)
fiber using a high-precision fiber coupling flexure stage or spectrally filtered first by passing it
through a monochromator and then coupling it into a fiber. The new setup also allows for free-space angle
and polarization resolved focused excitation of samples. The intensity of the laser output is controlled via a
pair of Glan Laser prisms (that also linearly polarize the beam) and neutral density filters.
The polarization of the free-space laser can be precisely set using a half-lambda wave plate.
This new laser source allows us to perform transmission, reflection or near-field experiments
on the Witec Microscope at any desired spectral range or monochromatic wavelength either in the visible
or infrared. Using a spectrometer with CCD detector (on order) an entire spectrum can be measured at
once which also allows for spectral imaging of samples (where every pixel in a 2D image contains an
entire spectrum). Finally, as a result of the pulsed output of the laser it is possible to use the source
for lifetime measurements as well. It should therefore even be possible in the future to measure lifetime
maps on a sample using the Fianium laser while scanning a sample using the Witec microscope.,
