The SmartLab apparatus, thanks to the peculiarity of its setup, offers the possibility to perform micro Raman and micro PL in a UHV ambient. In particular, the optical setup, realised in bulk optics on a damped optical table, is interfaced with a stage, adapted from a probe-microscopy one, hosted, along with the objective, in a UHV chamber.

The excitation frequency is provided by a solid state 532 nm Cobolt Samba laser

• Wavelength: 532.0 ± 0.3 nm

• Power @ 532 nm: 315 mW

•  Noise (pk-pk & rms) : 0.4 % & 0.05 %

• Power stability (8h): 0.8 %

The rejection of the elastic contibution is first provided by an Ondax beamsplitter (90/10) which drives the laser towards a laser grade Vacom viewport VPCF40DUVQ-L-LAMBDA10 in fused silica.

A UHV-compatible Attocube IT-APO532-RAMAN082 objective focuses the laser onto the sample

• Focal length: 2.88 mm

• Numerical aperture (NA): 0.82

• Working distance: 0.64 mm

• AR coating (> 80% trasnmission): 400 .. 1000 nm

• Apochromatic range (df < +/- delta): 520 .. 695 nm

• Laser spot size: 750 nm FWHM measured on a Au/Si sharp interface

Laser rejection is additionally guaranteed by the insertion of an Onadx LLN-532-OD4-2.5 notch filter.

SmartLab setup is equipped with two SpectraPro HRS-500 spectrographs by Princeton Instruments, in a double monocromator configuration

• Available gratings: 300 (1 um blaze), 1200 (750 nm blaze) and 1800 (500 nm blaze) grooves / mm

• Focal lenght: 500 mm

• Scan range: 0 - 1500 nm

• CCD spectral resolution: 0.07 nm

A PyLoN 100 BR eXcelon, back-illuminated and deep depletion CCD, and a PyLoN-IR, high-sensitivity InGaAs array, collect the light dispersed by the monochromator.

The sample holder is adapted from a Specs Hestia stage, a configuration realised with a Smaract exapod stage and a Janis ST-400 cryostat. Its coarse movements are closed loop encoder-controlled, and fine tuning position is obtained by piezos. 

• Six-axis stage: 3 translational d.o.f. ±3 mm, 2 tilt d.o.f ± 2 deg, 1 azimuthal d.o.f. ± 45 deg

• Linear bidirectional repeteability: 200 nm for whole translational travel range, ~ 7 nm for reduced (< 1 mm) travel range

• Minimun step: 1 nm

• Open cycle LHe, nominal consumption 0.6 l/h @ 5 K

• Lowest temperature achievable: ~ 15 K measured via InP excitons (see pictrue)

A spatial resolution better than 1 micron is also achievable due to the damping system supporting the UHV raman chamber, thus making it stable and decoupled against environmental vibrations.

A OSL2 fiber illuminator and a CS235CU scientific camera, both by Thorlabs, gives the possibility to access sample navigation and laser pointing.