Piezo stages

The output of a Nd YLF laser is focussed by a series of lenses to a spot size of 0.5 pm upon a sample which may be positioned by an x-y-z stepping motor stage and scanned by a computer-controlled high frequency x-y-z piezo stage. Ions are accelerated and transmitted through the central bore of the objective into a time-of-flight (TOF) mass spectrometer. The laser scans an area of 100 x 100 pm with a minimum step size of 0.25 pm. TOF mass spectra of each pixel are evaluated with respect to several ion signals and transformed into two-dimensional ion distribution plots. 

Tire between those two pairs. The delay Tjre was controlled with a piezo stage. The Tire was stabilized by the feedback loop control of the intensity of a CW He-Ne laser beam traveling as a reference beam through the same interferometer. 

The use of AFM has been expanded to measure the forces acting on an AFM tip as a function of separation between the tip and surface, but the tip geometry is often difficult to characterize and inconvenient to compare to theoretical predictions of force measurements. By attaching a colloidal size sphere (on the order of 5-10 (im in radius a) to the end of a cantilever (first accomplished by Ducker [26]), it is possible to measure the colloidal interaction between surfaces in system with a well-characterized geometry (shown schematically in Figure 4.2). The measurement of a force-distance cycle is the record of the deflection of the cantilever as the two surfaces approach through motion of the piezo stage. The separation distance between the surfaces is not measured directly... 

The pump-probe pulses are obtained by splitting a femtosecond pulse into two equal pulses for one-color experiments, or by frequency converting a part of the output to the ultraviolet region for bichromatic measurements. The relative time delay of the two pulses is adjusted by a computer-controlled stepping motor. Petek and coworkers have developed interferometric time-resolved 2PPE spectroscopy in which the delay time of the pulses is controlled by a piezo stage with a resolution of 50 attoseconds [14]. This set-up made it possible to probe decoherence times of electronic excitations at solid surfaces. 

For SPM applications, a piezo stage must be designed to move in x-, y- and z-directions. Several types of scanners have been technically realized (Fig. 10.4). Most common is a tube scanner in configuration B. Overall, piezo materials show a reliable performance for thousands of operation hours " , however, one has to be aware of possible hysteretic behavior" and piezo creep . 

From the vantage point of TCSPC, imaging by a piezo stage is a slow scan procedure. That means a full fluorescence decay curve is recorded in the current pixel before the scanner moves to the next one. Lifetime images can be therefore acquired by almost any TCSPC module and operation mode. Applications of onedimensional TCSPC with slow scanning are described in [76] and [74]. These... 

Figure 3 Block diagram of an apratureless reflection-back-to-the-fiber SNOM setup with shear-force distance controf and cross-polarization to minimize stray light (1) beam sphtto and crossed polarizers (2) shear-force arranganent (3) sample mounted on a piezo stage.

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