摘要:
This scanning near-field optical microscope is of the type where a light beam (19) with a diameter of at maximum λ/20 is emitted, or received, by a sharply pointed probe tip (13) which is scanned across the surface of a sample (11) to be investigated. The light reflected by, and/or transmitted through, the sample (11) is detected by a detector (16) and/or further processed by a computer (24). The distance between the light-emitting probe tip (13) and the sample (11) under investigation is on the order of λ/20 as well, so that the surface of the sample (11) is within the near-field of said probe tip (13). This optical microscope is characterized in that the gap between the probe tip (13) and the sample (11) is filled with a liquid (40) of high opacity, including any liquids with a large negative dielectric constant ε, so as to attenuate the intensity of the lightwaves emitted or received by the probe tip (13) to such an extent that the penetration depth z₀ of the lightwaves inside the liquid, defined as the distance over which their intensity decreases to 1/e, is below 100 nm.
摘要:
A sensor body (1) is formed as a light waveguide for laser light (2). A light exit site (10) for light diffracted within the sensor body (1) is located at a surface (6) thereof which faces away from a measured body (M). A detection particle (15) is located at the surface (5) of the sensor body (1) facing the measured body (M). It has a substantially convex and rounded off form and a major dimension which is smaller than the wavelength of the light (2). The measured body (M) is located in the optical near field of the detection particle (15). The latter has a major dimension of 5 to 500 nm and preferably of 20 to 100 nm. A detector means (11) converts the optical energy of the diffracted light to an electrical detector signal. A continuous thin film (16) is provided as a coating for the sensor (S). It substantially covers the detection particle (15) and at least part of the surface (5) of the sensor body (1) in the vicinity of the detection particle (15) It has a thickness which is smaller than one half of said predetermined wavelength. Preferably it is formed of gold and has a thickness of less than 100 nm. The sensor is used to finally convert a distance to an electrical quantity.
摘要:
The rotator comprises a piezoelectric bender (4) pivotally supported (2, 3) at one end and carrying a clamping means (6) to which a "payload" (7) may be attached. The bender (4) has split electrodes to keep its ends parallel when energized. Normally engaging the clamping means (6) are clamping members (15, 17) attached to a pair of piezoelectric benders (10,11) which are fixed in supports (12, 13) resting on a base plate (1). With the pair of benders (10, 11) energized, the clamping means (6) is released and energization of the central bender (4) results in the lifting of the payload (7) by one step. The clamping means (6) is then re-arrested and its pivot (2, 3) released by reversing the polarities at the pair of benders (10, 11), and the central bender (4) is permitted to stretch. the rotator is then prepared for the next step of rotation about the pivot (2). This embodiment permits rotation through about 15 degrees. Two further embodiments conceived for unlimited rotation are described.
摘要:
This distance-controlled tunneling transducer (1) comprises a plurality of sharply pointed tips (2) arranged in an array at tunneling distance from the electrically conductive surface (6) of a storage medium (7). Each tip (2) is attached to a cantilever beam (3) permitting the distance between each tip (2) and the surface (6) to be individually pre-adjusted by electrostatic means (8, 9). Arranged in juxtaposition with each cantilever beam (3) is a simple active control circuit (12, 13, 16) for adjusting the tip/surface distance during operation of a storage unit, thus preventing crashes of the associated tip (2) into possible asperities on the surface (6) of the recording medium (7). each control circuit (12, 13, 16) is designed such that its operating voltage, at the same time, serves to pre-adjust its associated cantilever beam (3) and to maintain the gap width essentially constant.
摘要:
In a preferred embodiment of this scanning tunneling microscope, the tunnel tip (15) consists of an optically transparent body coated with a semiconductor layer, such as a GaAs layer. The sample (19) being investigated consists of a magnetic material. Tunnel microscope operation permits to investigate the magnetic properties at or near the surface of the sample (19) if a spin-polarized beam of light (21) is shed onto the sample (19), either through the transparent body of the tunnel tip (15), from below through the sample (19), or from the side. In addition to conventional scanning tunneling microscope electronics (20), an oscillator-controlled (24) phase-sensitive detector or gating means (26) and a display unit (27) are provided for direct viewing of the magnetic properties and the topography of the sample (19).
摘要:
The waveguide comprises a transparent body (13) having a very sharp point at one end and being coated with a first opaque layer (14) such as metal. Said opaque layer (14) carries a layer (15) of an optically transparent material which, in turn, is covered by a second opaque layer (16). The apex of the point is removed so as to expose said transparent body (13) in a first aperture (18) and to expose said transparent layer (15) in a second aperture 17, said first aperture occupying an area below 0,01µm 2 . Light entering the transparent body (13) from its remote end is shone onto an object (4), the reflected light enters said second aperture (17) and is guided to a light detector (19) for further processing.