扫描系统: Piezoelectric scanners SPM scanners are made from a piezoelectric material that expands and contracts proportionally to an applied voltage. Whether they expand or contract depends upon the polarity of the applied voltage. Digital Instruments scanners have aC voltage ranges of +220 to-220V 0V No applied voltage Extended Contracted In some versions the piezo tube moves the sample relative to the tip In other models, the sample is stationary while the scanner moves the tip AC signals applied to conductive areas of the tube create piezo movement along the three major axes
Piezoelectric Scanners SPM scanners are made from a piezoelectric material that expands and contracts proportionally to an applied voltage. Whether they expand or contract depends upon the polarity of the applied voltage. Digital Instruments scanners have AC voltage ranges of +220 to -220V. 0 V - V + V No applied voltage Extended Contracted In some versions, the piezo tube moves the sample relative to the tip. In other models, the sample is stationary while the scanner moves the tip. AC signals applied to conductive areas of the tube create piezo movement along the three major axes. 扫描系统：
force sensor The force sensor is the part of AFM which measures the deflection of the cantilever. this includes a laser diode, a mirror and a photodetector (Quadrant or Dual element photodiode)
force sensor ⚫The force sensor is the part of AFM which measures the deflection of the cantilever. This includes a laser diode, a mirror and a photodetector(Quadrant or Dual element photodiode)
aser Mirror Photodetector cantilever Sample Ip RK e a tip is mounted on the cantilever such that, when the cantilever moves, the light beam from a small laser moves a cross the face of a four section photodetector. The amount of motion can then be calculated from the difference in light intensity on the sectors. Notice the advantage of the four sector detector over that of two sectors detector. The former can provide more information about the position of the cantilever in the x,y plane
⚫ A tip is mounted on the cantilever such that, when the cantilever moves, the light beam from a small laser moves a cross the face of a four section photodetector. The amount of motion can then be calculated from the difference in light intensity on the sectors. Notice the advantage of the four sector detector over that of two sectors detector. The former can provide more information about the position of the cantilever in the x,y plane
光检测器 General afm Beam deflection detection A Solid state Laser diode B Cantilever and Tip 横向偏转 悬臂 悬臂 位敏检测器 Used for Contact mode, non -contact and Tapping Mode AFM Laser light from a solid state diode is reflected off the back of the cantilever and collected by a position sensitive detector (PSD). This consists of two closely spaced photodiodes. The output is then collected by a differential amplifier Angular displacement of the cantilever results in one photodiode collecting more light than the other The resulting output signal is proportional to the deflection of the cantilever Detects cantilever deflection <1A
General AFM Beam Deflection Detection Used for Contact Mode, Non-contact and TappingMode AFM Laser light from a solid state diode is reflected off the back of the cantilever and collected by a position sensitive detector (PSD). This consists of two closely spaced photodiodes. The output is then collected by a differential amplifier Angular displacement of the cantilever results in one photodiode collecting more light than the other. The resulting output signal is proportional to the deflection of the cantilever. Detects cantilever deflection <1A Solid State Laser Diode Cantilever and Tip A B 光检测器
反馈控制系统 基本的反馈模式: (1〕恒力模式:接通反馈系统 (2)恒高度模式:关闭反馈系统
反馈控制系统 基本的反馈模式： （1〕恒力模式：接通反馈系统 （2〕恒高度模式：关闭反馈系统