Translation stage

Figure B2.1.2 Modified Michelson interferometer for non-collinear intensity autocorrelation. Symbols used rl, r2, retroreflecting mirror pair mounted on a translation stage bs, beamsplitter x, nonlinear crystal pint, photomultiplier Pibe.

In Table 4.3, the Cetac product LSX-200 is the specialized system for coupling with the ICP customer s system. It includes the laser, optical viewing system for exact positioning of the laser focus on a sample surface, and the sample cell mounted on the computer controlled XYZ translation stage. The system is also provided with the appropriate gas tuhing for transport of the ablated material into an ICP-OES/MS. 

The probe portion of the beam, on the other hand, goes to the cube mirror on the translation stage, which can move and thereby change the path length of the probe. The displacement of the translation stage determines the time delay between the pump and probe pulses. The time delay can be varied from I to 3 ns with the resolution of less than I fs. 

Fig. 1—Profile measurement technique of Champper 2000+. A surface measurement is made with a linearly polarized laser beam that passes to translation stage which contains a penta-prism. The beam then passes through a Nomarski prism which shears the beam into two orthogonally polarized beam components. They recombine at the Nomarski prism. The polarization state of the recombined beam includes the phase information from the two reflected beams. The beam then passes to the nonpolarizing beam splitter which directs the beam to a polarizing beam splitter. This polarizing beam splitter splits the two reflected components to detectors A and B, respectively. The surface height difference at the two focal spots is directly related to the phase difference between the two reflected beams, and is proportional to the voltage difference between the two detectors. Each measurement point yields the local surface slope [7].

A computer-controlled motorized translation stage mounted with a retro-reflector is used to vary the pump laser beam path relative to the probe laser beam path and this controls the relative timing between the pump and probe laser beams. Note that a one-foot difference in path length is about 1 ns time delay difference. The picosecond TR experiments are done essentially the same way as the nanosecond TR experiments except that the time-delay between the pump and probe beams are controlled by varying their relative path lengths by the computer-controlled motorized translation stage. Thus, one can refer to the last part of the description of the nanosecond TR experiments in the preceding section and use the pump and probe picosecond laser beams in place of the nanosecond laser beams to describe the picosecond TR experiments. 

Fig. 2 Flow coaler for creating polymer gradient thickness libraries A doctor blade B polymer solution C substrate D thickness library E x-translation stage F y-translation stage (for characterization).

More recently, NIST researchers [13, 19] developed a device to more precisely generate surface energy libraries using OV-ozonolysis. Pictured in Fig. 5, this device achieves graded UV-ozonolysis through a computer-driven translation stage. 

Fig. 3. Phase Locked IR Pulses Time domain interferometry. (A) Output IR pulses from two tunable OPA-DFGs in the 4-pm frequency regime. (B) Three examples of interferograms generated by these IR pulses. (C) Linear IR absorption spectrum of acetic acid overlapped with the output of two OPAs. (D) Photon echo signal from acetic acid upon t-scan. The x-axis is the delay of the translation stage and the insert is a blow-up of a small region.

The gel is left overnight without pressure so that equilibrium in the solvent at a fixed temperature is reached. The valve A in Fig. 2 is closed and the valve B is left open so that no pressure is exerted upon the gel. At the time zero of the measurement, the valve B is closed and A is opened immediately to apply the hydrostatic pressure to the gel. The position of the meniscus in the micropipette is measured as a function of time using a microscope on a mechanical translational stage with micrometers. After the measurement is done, the valve A is closed and the valve B is opened to release the pressure, which allows the gel to cover its initial state. 

There are several scan methodologies that can reduce the dead time. One method is to use a faster translation stage. An x-y stage driven by piezoelectric translators is preferred, because these stages settle in 0.001 s or less. While they can be incremented in steps as small as 10-20 nm, most are flexure (one-piece) designs and can travel only a few millimeters in either direction. Alternatively, the laser beam itself can be scanned, as commonly done in con-focal microscopy. Crossed galvanometer-driven mirrors have been used for this purpose, as have acousto-optic translators. 

Mount the tip of the micropipette in the electrode holder of the SECM translation stage. 

Fig. 4.1. Schematic diagram of the second harmonic generation experimental apparatus with the sample in the reflection geometry. The polarization analyzers are set to transmit p-polarized light at the frequency labeled in the figure. The (co/2co) filters transmit the (fundamental/harmonic) light while blocking the (harmonic/fundamental) light. For phase measurements, a quartz plate is mounted on a translation stage for movement towards the sample at a distance L.

Schematic diagram showing the integration of a polarization modulated birefringence apparatus within a laser Doppler velocimeter. This shows the side view. L light source (a diode laser was used) PSG rotating half-wave plate design LS lens FC flow cell (flow is into the plane of the figure) CP circular polarizer D detector 2D-T two dimensional translation stage 3D-T three dimensional translation stage LDVP laser Doppler velocimeter probe.

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