Laser Beam Analysis and Visualization

Elphel Model NC303 camera with a sensor with fiberoptic window may be used as a complete system for laser beam analysis and visualization. No special software needs to be installed on a host computer - the camera makes a "free ride" on a standard web browser and a VRML plugin for viewing 3D models. This approach made it possible to create a very compact device capable not only of laser beam image acquisition, but some image processing also. It provides:

• controlled background measurement and subtraction;
• visualization with user-defined pseudocolors - JPEG images with selectable compression ratio;
• standard beam parameters (centroid, diameter, aspect ratio, etc.) calculation;
• 3d interactive model generation including elevated mesh and lines of equal intensity - both flat and elevated according to their value. Once transferred to the host computer that model may be modified locally: zoomed, rotated, selectively shown/hidden some of the features, changed vertical scale and transparency. The model is a standard compressed VRML file that may be stored and imported into virtually any CAD software.

All the specific software is stored in the flash memory of the camera and may be easily updated using the files available for download. This software that runs in the camera under the control of GNU/Linux consists of three levels - each with the source code provided:

• Image acquisition driver - it can control different megapixel CMOS sensors currently available;
• CGI application (written in C) that accepts image acquisition/processing parameters and provides 2D images (JPEG), 3D models (compressed VRML) and data files in different formats (HTML, HTML+javaScript, XML);
• The HTML+javaScript page that plays the role of the user interface. It is made with regular web development tools and is the easiest part to modify.

You may see the actual size screen capture of the user interface of the software by clicking here or on the thumbnail image above.

If you are using IE you may also test drive the software in 2 modes - in both each button/icon has the explanation text (tooltips) that will pop up if you place a mouse cursor over it:

• Demo page that resides on a web hosting server and uses some previously acquired images/models/data files instead of the ones generated by the camera. That limits its capabilities but it responds faster than the
• Actual camera that is connected to the Internet via a limited bandwidth line so it is recommended that you first try the demo page to make sure it runs smoothly on your computer. The setup uses some pinhole made in aluminum foil illuminated by an LED instead of a laser, but the camera itself is a real thing.

You may also open the help page of the Elphel Laser Beam Analysis and Visualization System.