PicoScan Vibrometer
The PICOSCAN Vibrometer addresses the need for R&D and QC instrumentation that keeps pace with the ever increasing complexity of micromechanical systems. SmarAct’s vibrometer is developed for megapixel imaging of vibrational modes of microscopic structures. This is achieved by raster-scanning a tightly focussed laser beam of a Michelson interferometer over the sample to measure the vibrations for each pixel of the microscopic image. The PICOSCAN Vibrometer is equipped with a piezo-based sample shaker and a digital lock-in amplifier to measure amplitude and phase of the vibrations from which bending modes of up to 2.5 MHz can be reconstructed.
Unique features
The interferometer laser beam is used simultaneously to record a confocal reflection image of the sample, which is intrinsically aligned with vibration measurements. Thus an additional microscope imaging system is not required.
Even though the controller and UHV-compatible scanner are kept very compact, it provides structure scans with a size of 20 mm.
System components
PICOSCAN Vibrometer: contains an interferometer, function generator and lock-in amplifer (33 cm x 28 cm x 7.5 cm)
PICOSCAN Motion Controller: performs the closed loop operation of the XYZ positioners and contains a power amplifer for the shaker stage (33 cm x 28 cm x 7.5 cm)
XYZ scanner (10 cm x 5.5 cm x 7.5 cm) to raster-scan the focussing laser head over the sample
Granite plate (20 cm x 15 cm x 4 cm) with 2.5 cm diameter post for mounting the scanner
Shaker stage with holder
| Vibration measurement | |
| Working principle: | Michelson interferometer, single mode fibre coupled |
| Measurements laser: | 1550 nm DFB laser diode, stabilized (NIST traceable), Power output < 1 mW (Laser class 1) |
| Laser spot diameter at focus: | 7 µm |
| Resolution: | sub-pm for single point measurements, 0.1 nm in imaging mode |
| Imaging mode: | Amplitude and phase images can be analyzed with the included software or exported |
| Single point mode: | FFT spectrum from 1 Hz - 2.5 MHz with max. 2.5 million points |
| Digital lock-in amplifier | |
| Frequency range: | 500 Hz - 2.5 MHz |
| Reference signal: | Available through standard shaker stage and as output signal to drive custom actuators |
| Time constant: | Adjustable from 1 µs to 0.5 ms |
| Dynamic reserve: | >100 dB |
| Optical microscope | |
| Working principle: | Confocal laser scanning using the interferometer's measurement laser |
| Focus adjustment: | Manual or automatic with closed loop piezo drive |
| Lateral resolution: | 5 µm |
| Min. pixel size: | 1 µm |
| Max. image size: | 20 x 20 mm |
| Max. number of pixels: | 1000 x 1000 |
| Scanning motion system | |
| Working principle: | 3 axes linear piezo drive, closed loop |
| Resolution: | 1 nm |
| Repeatability: | 30 nm |
| Max. travel: | 20 mm (others on request) |
| Dimensions | |
| Controller: | 2 units of each 33.0 x 27.0 x 7.0 cm (W x L x H) |
| Scanner mount: | Granite stone 15.0 x 20.0 x 4.0 cm (W x L x H) with stainless steel post 2.5 x 15.0 cm (d x H) |
| Scanning stage: | 5.5 x 11.0 x 7.5 cm (W x L x H) |
| Shaker stage: | Stainless steel 8.0 x 1.5 cm (d x H) |
