Benm
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- Aug 16, 2007
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Here are a couple of pictures, showing that the A140 445 nm diode produces some green lines when driven far below lasing threshold. The first picture is the laser running at ~5 mA, where you can see some greenish lines produced by the impurities in the diode.
The other pictures shows it at a bit more current, but still far below lasing threshold - the green is no longer perceptible.
This effect is similar to blue power leds producing often yellow light at very low voltages, but its very difficult to produce with these diodes, just a tad more current and the blue completely overwhelms the green lines - the semicondutive materials used in these diodes appear to be pretty pure.
The other pictures shows it at a bit more current, but still far below lasing threshold - the green is no longer perceptible.
This effect is similar to blue power leds producing often yellow light at very low voltages, but its very difficult to produce with these diodes, just a tad more current and the blue completely overwhelms the green lines - the semicondutive materials used in these diodes appear to be pretty pure.