An atomic force microscope tip as a light source

Abstract

We present a simple method for causing the end of a silicon nitride atomic force microscope (AFM) tip to emit light, and we use this emitted light to perform scanning near-field optical microscopy. Illumination of a silicon nitride AFM tip by blue (488nm) or green (532nm) laser light causes the sharp part of the tip to emit orange light. Orange light is emitted when the tip is immersed in either air or water; and while under illumination, emission continues for a period of many hours without photobleaching. By careful alignment of the incident beam, we can arrange the scattered light to decay as a function of the tip-substrate separation with a decay length of 100–200nm. The exponential decay of the intensity means that the emitted light is dominated by contributions from parts of the tip that are near the sample, and therefore the emitted orange light can be used to capture high-resolution near-field optical images in air or water.

High-speed atomic force microscopy for nano-visualization of dynamic biomolecular processes

“…There have been a number of reports on conventional slow AFM combined with confocal fluorescence [228][229][230][231], conventional Raman scattering [232,233], coherent anti-Stokes Raman scattering [234,235], or TIRF [236][237][238] microscopes. When the simultaneous recording of optical and AFM images is required, some precautions are necessary regarding the luminescence of the cantilever tip [239][240][241] and the photothermal bending of the cantilever [111]. In tapping-mode AFM, the DC deflection of a cantilever does not affect AFM imaging; thus, the photothermal bending of the cantilever should not be a problem provided its bending is not too large and the light power is stable.…”

Near-Field Scanning Optical Microscopy Enables Direct Observation of Moiré Effects at the Nanometer Scale

“…To characterize the produced nanostructures, a home-constructed multifunctional microscope combining atomic force microscope (AFM), near-field scanning optical microscope (NSOM), and far-field optical microscope was used. ,, The detailed setup and operation has been reported previously. The near-field scanning optical microscopy used for this work follows an apertureless configuration. , Figure A shows the schematic of the optical path.…”

“…However, conventional aperture NSOM has great difficulty detecting the Moiré effect due to low photon throughput, difficulties in operation, and insufficient spatial resolution. This work utilizes a home-built apertureless NSOM for the investigation of the Moiré effect. , In this design, NSOM light source was produced by excitation of commercial silicon nitride (Si 3 N 4 ) AFM probes with an ultraviolet laser ( e.g. , 405 nm).…”

“…This work utilizes a home-built apertureless NSOM for the investigation of the Moiré effect. 32,33 In this design, NSOM light source was produced by excitation of commercial silicon nitride (Si 3 N 4 ) AFM probes with an ultraviolet laser (e.g., 405 nm). Such a light source has the intrinsic advantages of stability, durability, and high emission intensity.…”

High-speed AFM and nano-visualization of biomolecular processes

“…When simultaneous recording is required, various precautions are necessary. Cantilever tips of amorphous silicon and amorphous silicon nitride are known to be strongly photoluminescent [44][45][46], while crystalline silicon tips are much less luminescent [33]. EBD carbon tips are also less luminescent.…”