Single Point Laser Vibrometer
What is the Laser Vibrometer?
- Recording substrate-transmitted vibratory signal in animal has been difficult and hindered by the lack of reliable measuring device. In the past, various equipments have been used to record substrate-transmitted vibratory signal, such as bamboo membrane and microphone, microphone and gramophone pickup. Such equipments are hard to operate, prone to noise and tend to distort measurements because of their mass.
- Laser Vibrometer is a device utilize laser beam to make non-contact vibration measurements of a surface. The laser beam is directed at the surface of interest (e.g. plant leave, social insects nest, surface where insect stand, etc) and the vibration amplitude and frequency are extracted from the modulation of the laser beam due to the motion of the surface.
- In our Laser Vibromete a red laser pointer beam gets reflected by a retro-reflective foil, the reflected light generates an interference speckle patterns on surfaces around the laser beam. At ~1m from the reflector, the speckles are spaced 1- 3 mm. If the reflector is vibrated, the speckle pattern moves fiercely. The concomitant modulation of the il luminance of a photodiode is used to detect the movements of the speckles and hence the vibration generated by animal.
- The Laser Vibromete enables for a precise measurement and characterization of substrate-transmitted vibratory signals.
- In contrast to the Laser Doppler Vibrometer, our Laser Vibrometer in far less expensive because it does not utilize expensive optics to detect the reflected laser beam, it rather use inexpensive
to send back the laser beam to the device where it is detected by
Field of application:
- Vibratory signal plays an important part in communication in almost all species; Laser Vibrometry can be used to measure such vibration in great details. For example many insects communicate using substrate born signal. Some insect sounds are quite loud, such as the singing of the cicada, while others are ultrasonic and can’t be heard. Some insects are so small that their songs are transmitted mainly through a plant rather than air. Researchers can use the Laser Vibrometers to record this unheard noise. Characterization of such signal will enable better understand the evolution and ecology of a given species. In some circumstances once acoustic signal has been characterized it can be used for management of unwanted organisms, e.g. disruption of communication.
Recording vibrational sound from gyne Vespula germanica using Laser Vibrometer
To order the Laser Vibrometer for your laboratory please contact:
Dr. Ashraf M. El-Sayed
The Pherobase (www.pherobase.com)
Christchurch, New Zealand