…because soon we have coffee break! And you don’t want to miss it this time…
If you have heard something about the taste, please make a comment ;). It seems that they enjoy their coffees and tea.
To heat the water they used a continuous wave Nd:YAG laser with a maximum power of 2.5kW at 1064nm. The wavelength is already in the near infrared range and therefore not visible to our eyes. This type of laser is very often used in industry for material processing. Unfortunately, I couldn’t find more information about this group, what they are mainly working. Looking around in their laboratory I guess it is not an optics group but probably an engineering group – working somehow on material processing.
Have you already asked yourself, why we see the laser beam even it should be invisible for our eyes? The reason is simple. The digital camera with the CCD sensor (Nobel Prize this year!) is sensitive at these wavelengths too. Normally, the camera blocks the near infrared and infrared spectral range by a filter. If you watch carefully the movie, you will notice that they change the camera to their research camera where they do not have such a filter (after 42 seconds). Hence, the laser light scattered by the water can be detected by this camera and we can see the laser light on the camera screen.
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In order to view laser through a CCD camera, can you suggest a brand and model or would any CCD pick up laser?
ReplyDeleteThank you.
Hi,
ReplyDeleteit depends which wavelength your laser has. A normal standard CCD camera (respectively beam profiler) has a wavelength range between 350nm to 1150nm). Means, with such a camera you could see the beam in the video (1060nm). However, with such a camera you only see something if the beam hits the camera. I guess what you want is a so called Infrared Viewer. With such a device you can "see" the laser beam. Because "normally" there is enough dirt and dust in the air, where the beam gets a bit scattered (and this is what you see).
This devices are standard products and can be bought at nearlly all optic distributors like Thorlabs or Newport (search with beamprofiler and infrared viewer).
For the beamprofiler we are using quite often "WinCam" from DataRay (http://www.dataray.com/)
Infrared viewer (newport): http://search.newport.com/?q=*&x2=sku&q2=IRV2-2000
hope your question is answered.
best
Kroko