Scanning Near Field Optical Microscopy (SNOM) is an advanced imaging technique that breaks the diffraction limit of conventional optical microscopy. By using a nanoscale light source, SNOM provides exceptional spatial resolution reaching down to 100nm and enables the visualization of structures at the nanometer scale. At LFOS, TriA-SNOM works in aperture mode. In this mode, the near field light is created by using an appropriate SNOM probe with an aperture at the tip. The diameter of this aperture (d) is smaller than the wavelength (λ) of the used light. The incident light is coupled into a metal covered optical fiber with a tip aperture (d≪λ). During scanning, the tip-sample distance is regulated and maintained constant by a Feedback control system based on ˝shear force˝ interaction. This is also equipped with two detectors for SNOM optical signal acquisition (reflection and transmission). The entire setup is enclosed in a Faraday box to reduce the electromagnetic noise. Furthermore, the entire SNOM head has a passive damping system with floating marble base which is used an anti-vibration tool.
With this microscope, we can conduct examinations of variety of materials, including biological specimens, polymers, semiconductors, and nanostructures. At LFOS, SNOM is used to investigate the photoconductive properties of organic and 2D materials, enhancing the understanding of their potential for optoelectronic applications. Currently, the set up is equipped with a pre-amplifier, lock-in amplifier, voltage supplier thereby enabling the measurements of currents as low as pA.
List of equipments:
- Variable Gain Low Noise Transimpedance Amplifier (Current Amplifier) DLPCA-200
- MFLI Lock-in Amplifier 500kHz / 5MHz 60MSa/s (Zurich Instruments
- High voltage amplifier (A.P.E.Research)
- SPM control unit (A.P.E.Research)
- Laser Source (A.P.E.Research)
Person in charge:
Equipment location:Laboratory LFOS, University of Nova Gorica, Vipavska c. 11c, Ajdovščina, Slovenia.
Equipment accessibility: from Monday to Friday between 8 a.m and 4 p.m., or else in preceding accordance with the person in charge.