Dual STM and NSOM for SPP Excitation and Collection

 MV4000 Dual Probe function provides a flexible platform for simultanous STM and NSOM functionality. Such platform is ideal for surface plasmons (SP) excitation with an STM probe and effective imaging of the SP both in aperture NSOM and apertureless via photon tunneling process.
The following scheme describes the dual probe setup for excitation of surface plasmons on 35nm gold coated surface. The second probe is an NSOM probe use for localized AFM/NSOM imaging of the generated surface plasmons at nanometric close proximity from the STM excitation probe.  

 Left: Dual probe Setup for SPP excitation with STM probe and near-field imaging with a second NSOM probe. The multiprobe setup allows for clear optical access from above and below without any obscuration. Right: An optical microscope image from above shows dual probe STM/NSOM in during operation. Cantilevered bent probes allows for clear optical access and for multiprobe operation at close proximity. 

AFM NSOM Imaging of Surface Plasmons excited with STM Probe 

Simultanous AFM-NSOM imaging of surface plamsons with an apertured NSOM probe. The cantilvered NSOM and STM probes gepometry allows for bringing the NSOM probe to a close proximity from the excitation STM probe and thus allows mapping of the SP the point where they are generated. In addtion, MultiView 4000 system incorporates sample scanning and tip scanning piezo stages and thus allows for flexible and accurate positioning of both probes until achieving "soft-contact" between the probes. Such procedue of two probe distance adjustement is performed while the two probe are kept in feedback with the sample and thus allows for safe probes nanomanipulation.

The imaged below shows the results of the above protocols obtained by the NSOM probes in probe scanning mode.

Simultanous AFM Height (Left) and NSOM (Right) images performed with the aperture NSOM probe starting from the STM tip position (placed at a stationary position at the bottom side of the above image)

 Ultra Sensitive Tuning Fork for AFM/STM Feedback

MV4000 multiprobe system uses ultrasensitive Tuning Fork feedback which is ideal for such combined AFM and STM feedback. The tuning fork high force sensitivity and lack of jump-to-contact allows for defined tip-sample interaction down to close proximity from the sample (<1nm) without any force discontinuity (which does occur in optical feedback AFM techniques, during to jump-to-contact and ringing adhesion effects). Such distance stability permits obtaining simultaneous AFM and Tunneling

Ultrasensitive tuning fork AFM-STM feedback with Normal Force AFM/NSOM cantilevered and exposed probes.

Unique AFM-STM probes

Nanonics uniquely provides probes which are able to scan with either AFM or STM feedback using the same probe with easy switching between modes

AFM STM Probe acting in Normal Force with tuning fork feedback

 Single and multiple atomic steps imaging with AFM and STM feedback. Line profiles of HOPG steps with AFM feedback (middle) and STM feedback (Right) performed with the same probe.

 Nanonics MultiView AFM/STM system has been used for obtaining Work Function information on Q-Dot using Tunneling Feedback.  See more information: Nano Lett. 2013, 13, 2338−2345