This invention involves measurement of optical properties of materials with sub-micron spatial resolution through infrared scattering scanning near field optical microscopy (s-SNOM). Specifically, the current invention provides substantial improvements over the prior art by achieving high signal to noise, high measurement speed and high accuracy of optical amplitude and phase. Additionally, it some embodiments, it eliminates the need for an in situ reference to calculate wavelength dependent spectra of optical phase, or absorption spectra. These goals are achieved via improved asymmetric interferometry where the near-field scattered light is interfered with a reference beam in an interferometer. The invention achieves dramatic improvements in background rejection by arranging a reference beam that is much more intense than the background scattered radiation. Combined with frequency selective demodulation techniques, the near-field scattered light can be efficiently and accurately discriminated from background scattered light. These goals are achieved via a range of improvements including a large dynamic range detector, careful control of relative beam intensities, and high bandwidth demodulation techniques. In other embodiments, phase and amplitude stability are improved with a novel s-SNOM configuration. In other embodiments an absorption spectrum may be obtained directly by comparing properties from a known and unknown region of a sample as a function of illumination center wavelength.

An image processing method of two-photon structured illumination point scanning microscopy is disclosed. The image processing method includes the following steps: providing a laser light source; performing scanning and recording; and performing image reconstruction. The laser light source, which has photon energy that is half of the energy needed to let a molecule of a sample make a transition from ground state to a first excited state, is focused onto a focal plane of the sample. Then, the laser light source is accompanied with an image recording system to perform a plurality of segmented scanning and image recordings on the sample to generate a plurality of structured illumination images. Those structured illumination images are reconstructed to generate microscopic image of the sample. With the implementation of the present invention, the interference from image signal on the non-focal plane can be effectively reduced, thereby enhancing the resolution of microscopic image.

A method for testing an integrated circuit (IC) using a nanoprobe, by using a scanning electron microscope (SEM) to register the nanoprobe to an identified feature on the IC; navigating the nanoprobe to a region of interest; scanning the nanoprobe over the surface of the IC while reading data from the nanoprobe; when the data from the nanoprobe indicates that the nanoprobe traverse a feature of interest, decelerating the scanning speed of the nanoprobe and performing testing of the IC. The scanning can be done at a prescribed nanoprobe tip force, and during the step of decelerating the scanning speed, the method further includes increasing the nanoprobe tip force.

This invention involves measurement of optical properties of materials with sub-micron spatial resolution through infrared scattering scanning near field optical microscopy (s-SNOM). Specifically, the current invention provides substantial improvements over the prior art by achieving high signal to noise, high measurement speed and high accuracy of optical amplitude and phase. Additionally, it some embodiments, it eliminates the need for an in situ reference to calculate wavelength dependent spectra of optical phase, or absorption spectra. These goals are achieved via improved asymmetric interferometry where the near-field scattered light is interfered with a reference beam in an interferometer. The invention achieves dramatic improvements in background rejection by arranging a reference beam that is much more intense than the background scattered radiation. Combined with frequency selective demodulation techniques, the near-field scattered light can be efficiently and accurately discriminated from background scattered light. These goals are achieved via a range of improvements including a large dynamic range detector, careful control of relative beam intensities, and high bandwidth demodulation techniques. In other embodiments, phase and amplitude stability are improved with a novel s-SNOM configuration. In other embodiments an absorption spectrum may be obtained directly by comparing properties from a known and unknown region of a sample as a function of illumination center wavelength.

This invention involves measurement of optical properties of materials with sub-micron spatial resolution through infrared scattering scanning near field optical microscopy (s-SNOM). Specifically, the current invention provides substantial improvements over the prior art by achieving high signal to noise, high measurement speed and high accuracy of optical amplitude and phase. Additionally, it some embodiments, it eliminates the need for an in situ reference to calculate wavelength dependent spectra of optical phase, or absorption spectra. These goals are achieved via improved asymmetric interferometry where the near-field scattered light is interfered with a reference beam in an interferometer. The invention achieves dramatic improvements in background rejection by arranging a reference beam that is much more intense than the background scattered radiation. Combined with frequency selective demodulation techniques, the near-field scattered light can be efficiently and accurately discriminated from background scattered light. These goals are achieved via a range of improvements including a large dynamic range detector, careful control of relative beam intensities, and high bandwidth demodulation techniques. In other embodiments, phase and amplitude stability are improved with a novel s-SNOM configuration. In other embodiments an absorption spectrum may be obtained directly by comparing properties from a known and unknown region of a sample as a function of illumination center wavelength.

A scanning probe microscope and method of operating the scanning probe microscope selects a preferred focus position of a focused optical beam on a probe of the scanning probe microscope by adjusting a focus position of the focused optical beam on the probe relative to a tip of the probe and then measuring at least one of a response of the probe and optical radiation scattered from the probe as a function of the position of the focused optical beam. The preferred focus position of the focused optical beam on the probe is based on the measuring of the at least one of the response of the probe and the optical radiation scattered from the probe.

A scanning probe microscope and method of operating the scanning probe microscope selects a preferred focus position of a focused optical beam on a probe of the scanning probe microscope by adjusting a focus position of the focused optical beam on the probe relative to a tip of the probe and then measuring at least one of a response of the probe and optical radiation scattered from the probe as a function of the position of the focused optical beam. The preferred focus position of the focused optical beam on the probe is based on the measuring of the at least one of the response of the probe and the optical radiation scattered from the probe.