attoSNOM III
fiber based, low temperature scanning near-field optical microscope, tuning fork sensor
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he attoSNOM III uses a non-optical, tuning fork based distance control system for highest stability and accuracy. This control system uses a piezoelectric quartz sensor for highly sensitive shear force detection and an electronic feedback loop (phase-locked loop, PLL) to keep the tip-sample separation constant. In addition to these mechanical properties, a high-quality optical fiber probe tip ensures highest light throughput and resolution.
As an optional configuration, the system can also be equipped with an ellipsoidal aluminum mirror in order to collect the signal scattered by the sample surface. Overall, the attoSNOM III impresses by its outstanding sensitivity combined with high spatial resolution.

The attoSNOM III is compatible with any fiber-based SNOM probe.

	01 LT and HV compatible feedthroughs 02 vacuum window 03 microscope insert 04 superconducting magnet (optional) 05 liquid He dewar (optional) 06 ultra stable Titanium housing 07 xyz coarse positioners 08 xy scanner 09 sample 10 single mode SNOM fiber 11 tuning fork including LT compatible preamplifier
Scheme of a cryogenic tuning fork based SNOM insert including cryostat and superconducting magnet.

Principle - The excellent spatial resolution of the attoSNOM III is achieved by approaching the aperture of an aluminum coated, tapered optical fiber tip to close proximity of the sample surface and by precisely controlling the tip-sample separation by means of a tuning fork sensor. In order to achieve highest stability and to minimize parasitic cable capacitance, the tuning fork is directly mounted onto a low temperature preamplifier. In a typical imaging application, the vibrational amplitude of the tip is adjusted to about 50 pm and the tip-sample separation is kept constant by using a phase-locked loop and a PI controller on the frequency shift. The optical fiber-based probe is used to illuminate or excite the sample surface locally. The reflected signal containing the information about local sample surface properties (such as refractive index, chemical properties, photoluminescence etc.) is either collected through the same fiber or by an ellipsoidal aluminum mirror (optional).

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Detailed Specification Sheet

Complete System Solutions:
attoCRYO	Complete system configurations for this product.