Abstract: The invention relates to a coolable optical table with a table top and at least three table legs. Securing means for securing objects such as optical elements are provided in a table surface of the table top. The table legs are equipped with a damping device for damping vibrations.

Abstract: An electromechanical actuator includes a base part and an oscillation resonator having the shape of a rod. The electromechanical actuator further includes amount for mounting the oscillation resonator to the base part. The mount is configured to bear the oscillation resonator so as to be rotatable around an axis of the oscillation resonator rod relative to the base part. A driver member is mechanically coupled to the oscillation resonator. A slider or a rotator is configured to be moved by the driver member when the oscillation resonator is excited.

Abstract: The invention relates to a table having a tabletop and including a refrigerating machine, at least one section of the tabletop being coolable by means of the refrigerating machine via a thermal contact; an upper vacuum chamber, which can be evacuated, for thermally insulating the thermal contact from a surrounding area of the table, said chamber connecting an upper face of the refrigerating machine facing the tabletop and the section to be cooled, and which has at least one flexible upper chamber section; a lower vacuum chamber, which can be evacuated, which is connected to a lower face of the refrigerating machine facing away from the tabletop, and which has at least one flexible lower chamber section; and a rigid stiffening structure, which is connected to the refrigerating machine via the flexible upper chamber section and via the flexible lower chamber section.

Abstract: An electromechanical actuator includes a base part and an oscillation resonator having the shape of a rod. The electromechanical actuator further includes amount for mounting the oscillation resonator to the base part. The mount is configured to bear the oscillation resonator so as to be rotatable around an axis of the oscillation resonator rod relative to the base part. A driver member is mechanically coupled to the oscillation resonator. A slider or a rotator is configured to be moved by the driver member when the oscillation resonator is excited.

Abstract: An electromechanical actuator includes an oscillation resonator having the shape of a rod. The oscillation resonator is divided by a dividing plane that is not parallel to the longitudinal direction of the oscillation resonator into a first resonator portion and a second resonator portion. At least the first resonator portion includes electromechanical means which, when activated, are configured to generate a 3-dimensional acoustic bulk wave are with a mode shape asymmetric with respect to the dividing plane.

Abstract: A device for absolute distance measurement includes a first tunable light source for emitting a first wavelength light of a first tunable frequency modulated by a first modulating frequency and a second light source for emitting a second wavelength light of a second frequency modulated by a second modulating frequency. An optical coupler couples the first wavelength light and the second wavelength light into an interferometer cavity. An interferometer detector provides an interference measurement signal based on a detected interference pattern. A demodulator unit generates a first demodulation signal based on the interference measurement signal by demodulation with the first modulating frequency and a second demodulation signal based on the interference measurement signal by demodulation with the second modulating frequency. A computation unit computes an absolute distance by evaluating the first demodulation signal acquired during a sweep of the first tunable frequency and the second demodulation signal.

Abstract: The invention relates to a table having a tabletop and including a refrigerating machine, at least one section of the tabletop being coolable by means of the refrigerating machine via a thermal contact; an upper vacuum chamber, which can be evacuated, for thermally insulating the thermal contact from a surrounding area of the table, said chamber connecting an upper face of the refrigerating machine facing the tabletop and the section to be cooled, and which has at least one flexible upper chamber section; a lower vacuum chamber, which can be evacuated, which is connected to a lower face of the refrigerating machine facing away from the tabletop, and which has at least one flexible lower chamber section; and a rigid stiffening structure, which is connected to the refrigerating machine via the flexible upper chamber section and via the flexible lower chamber section.

Abstract: An electromechanical actuator includes an oscillation resonator having the shape of a rod. The oscillation resonator is divided by a dividing plane that is not parallel to the longitudinal direction of the oscillation resonator into a first resonator portion and a second resonator portion. At least the first resonator portion includes electromechanical means which, when activated, are configured to generate a 3-dimensional acoustic bulk wave are with a mode shape asymmetric with respect to the dividing plane.

Abstract: A device for absolute distance measurement includes a first tunable light source for emitting a first wavelength light of a first tunable frequency modulated by a first modulating frequency and a second light source for emitting a second wavelength light of a second frequency modulated by a second modulating frequency. An optical coupler couples the first wavelength light and the second wavelength light into an interferometer cavity. An interferometer detector provides an interference measurement signal based on a detected interference pattern. A demodulator unit generates a first demodulation signal based on the interference measurement signal by demodulation with the first modulating frequency and a second demodulation signal based on the interference measurement signal by demodulation with the second modulating frequency. A computation unit computes an absolute distance by evaluating the first demodulation signal acquired during a sweep of the first tunable frequency and the second demodulation signal.

Abstract: Device and method for acquiring position with a confocal Fabry-Perot interferometer. In a general aspect, the device for acquiring position may include an arrangement for acquiring position where the acquiring arrangement has a confocal Fabry-Perot interferometer. In another general aspect, a method for acquiring position may include generating an interference pattern dependent on a position of an object by a confocal Fabry-Perot interferometer; detecting the interference pattern to obtain a measuring signal; and evaluating the measuring signal.

Abstract: An apparatus for position finding, including a light source to produce a wave field in a measurement section, a wave field variation device to generate a variation of a wavelength of the wave field over time, an interferometer to produce an interference pattern for the wave field which is dependent on the length of the measurement section, a detector to produce a measurement signal on the basis of the detected interference pattern, and an evaluation circuit to evaluate the measurement signal on the basis of the variation over time.

Abstract: Device and method for acquiring position with a confocal Fabry-Perot interferometer. In a general aspect, the device for acquiring position may include an arrangement for acquiring position where the acquiring arrangement has a confocal Fabry-Perot interferometer. In another general aspect, a method for acquiring position may include generating an interference pattern dependent on a position of an object by a confocal Fabry-Perot interferometer; detecting the interference pattern to obtain a measuring signal; and evaluating the measuring signal.

Abstract: An apparatus for position finding, including a light source to produce a wave field in a measurement section, a wave field variation device to generate a variation of a wavelength of the wave field over time, an interferometer to produce an interference pattern for the wave field which is dependent on the length of the measurement section, a detector to produce a measurement signal on the basis of the detected interference pattern, and an evaluation circuit to evaluate the measurement signal on the basis of the variation over time.

Abstract: An inertial positioning device comprising: a base plate (10); a top plate (20) for mounting an element to be rotated; a rotation member (16) having a column (18) on which the top plate is mounted in frictional engagement for slip-stick rotational motion; and a pair of piezoelectric actuators (12) each secured to the base plate at one end and to lateral extensions (17) of the rotation member at their other ends. Simultaneous actuation of the piezoelectric actuators rotates the column of the rotation member about its axis. When a suitable asymmetric drive signal is supplied to the piezoelectric actuators, the top plate is rotated by slip-stick motion. The device is compact, has a good load capacity for an inertial motor and is operable in extreme environments such as liquid helium temperatures, high vacuum and high magnetic fields.

Abstract: An inertial positioning device comprising: a base plate (10); a top plate (20) for mounting an element to be rotated; a rotation member (16) having a column (18) on which the top plate is mounted in frictional engagement for slip-stick rotational motion; and a pair of piezoelectric actuators (12) each secured to the base plate at one end and to lateral extensions (17) of the rotation member at their other ends. Simultaneous actuation of the piezoelectric actuators rotates the column of the rotation member about its axis. When a suitable asymmetric drive signal is supplied to the piezoelectric actuators, the top plate is rotated by slip-stick motion. The device is compact, has a good load capacity for an inertial motor and is operable in extreme environments such as liquid helium temperatures, high vacuum and high magnetic fields.

Abstract: A sample holder apparatus for a top-loading cryostat insert based on a cage assembly system which is mounted onto a vacuum flange. The vacuum flange has a group of blind bores on the vacuum side of the flange, in which are mounted hollow cage assembly rods, and a further corresponding group of four blind bores on the air side of the flange for receiving further cage assembly rods. A cage assembly system can thus be provided on the vacuum side of the flange and, if desired, extended through the vacuum flange onto the air side with optical communication between the vacuum and air sides taking place through a window at the top of the flange. Feed-throughs on the flange provide for access of optical fibers and electrical leads. The design provides a sample holder which is readily adaptable and reconfigurable to perform a variety of optical experiments in a top-loading cryostat. Examples of near-field scanning microscopy (NSOM) and confocal microscopy are described.

Abstract: A head for a scanning probe microscope comprising a tuning fork (130) with an SPM tip (134) attached to one prong of the tuning fork. An AC signal (Vin) generated by oscillation of the tuning fork is supplied by a pair of electrodes on the tuning fork to input terminals (110 and 112) of a source-follower circuit comprising a dual-gate GaAs-MESFET (114), the gates (G1, G2) of which are connected in parallel to one of the pick-up electrodes via one of the input terminals (110), the other of the pick-up electrodes being earthed via the other of the input terminals (112). The signal (Vin) is processed by the circuit and supplied to two output terminals (126 and 128) as an output signal (Vout). The megaohm output impedance of the tuning fork is thus translated into an output impedance of the order of a hundred ohms, thus improving signal transfer efficiency from the head to an external signal amplifier.

Abstract: An inertial positioner comprising a base plate and a carriage plate (2) slidably connected to one another via a bearing assembly (3) so as to allow relative movement of the plates in a positioning direction. The bearing assembly (3) comprises two sets of caged ball bearings seated in respective pairs of V-grooves (25 and 26) formed in the facing surfaces of the base and carriage plates, the V-groove pairs extending spaced apart in the positioning direction. An actuator comprising a piezoelectric element (4) and a rod (5) extends between the plates (1 and 2), the piezoelectric element (4) being secured to the carriage plate (2) and the rod (5) forming a frictional engagement characterized by a force F with the base plate via a collar (20) fastened to the base plate via biasing means (not shown). In operation, a periodic saw-tooth voltage is applied to the piezoelectric element (4) to produce motion.

Abstract: A method and apparatus for determining the optical aperture diameter `d` of tips suitable for use in near-field scanning optical microscopy (NSOM). Several functional relationships are found between the far-field angular intensity distribution function I(.theta.) for light of wavelength `.lambda.` emitted out of the aperture, the angle `.theta.` being that formed between the direction of travel of the photon concerned and the perpendicular to the plane of the aperture. It is found that I(.theta.) depends sensitively on the aperture `d`. In one embodiment tip diameters can be measured for diameters in the range of .lambda./6<d<.lambda..

Abstract: A scanning probe microscope, in particular for near-field scanning optical, friction force and atomic force microscopy, comprises a tip piece attached to an oscillator of piezoelectric material. This oscillator is coupled to a further oscillator thereby forming a coupled oscillator arrangement. In a most preferred embodiment, the coupled oscillator arrangement is a quartz piezoelectric tuning fork. In use, the tip piece is vibrated relative to the sample. Tip-sample interaction strains the piezoelectric material and is measurable via contacts placed on the piezoelectric material which are responsive to the strain-induced piezoelectric charge. The coupled oscillator arrangement allows a large Q of several thousand or more to be realized. The microscope is easy to operate due to the purely electrical signal collection. The probe head can operate in vacuum, at cryogenic temperatures or in high magnetic fields.