Triple-wavelength optical pickup head designs for compact disk, digital versatile disk and high-density digital versatile disk devices

We present a triple-wavelength design for a compact optical pickup head which uses two rhomboid prisms in parallel with three laser diodes. The design can be used for compact disk, digital versatile disk and high-density digital versatile disk devices. The specific prism lens used decreases the geometrical size and reduces the total number of optical components. The trade-off between tolerance and fabrication is also presented.