Light Source:  
  • Type (cw laser, pulsed laser, LED, other)
  • Wavelength (center and bandwidth)
  • Polarization
  • Power/Energy (average and/or peak)
  • Beam profile (diameter, divergence, M² quality)
  Optical Function:    
  • Desired light field distribution (shape, uniformity)
  • Working distance
  • Field of view / Diffraction angles
  • Target surface inclination and/or shape
  • Eye Safety requirements
  • Element form factor (size, shape)
  • Element material
  • Environmental conditions
  • Packaging of elements
  • Sensor and/or screen type for light field (CCD/CMOS/ human eye/…)
  Last but not least, the target annual production and a price target are required to choose the best solution.  

Laser keyboard by a DOE
We tested our designed and fabricated laser keyboard DOE on 31 July 2012. The following picture shows the image of the actual laser keyboard, which was taken with a point-and shoot camera in natural light. Click the picture to see a larger image.