Coté Fq, ça ne devrait pas bouger, laser, c'est laser, donc cohérent et stable à priori !
Mais vu la chaîne opto électronique pour faire vu vert à partir du rouge, hum ... bon...
A part cela, la température interne devrait rapidement monter et se stabiliser à l'usage (Juste mon idée)
Plus les batteries au froid, essayer les Li-Ion ??
J'ai trouvé une explication qui semble bonne :
Greens are VERY temperature sensitive.
Red lasers are a single stage diode. The electricity goes in, and it lights up.
Greens are much more complicated. The electricity goes in, the infra red diode at a frequency of 808nm lights up, and because of all the jumps and stages it'll go through next, it's way more powerful than the output wattage you'll actually get in green at the end.
The 808nm IR laser light then passes into a Nd:YVO4 (Neodymium, Yittrium, Vanadium, Oxygen...) crystal that absorbs the 808nm IR laser light, and re-lases in an even lower IR frequency of 1064nm IR light. It then passes into a second crystal, called the KTP (Potassium Titanyl Phosphate) which absorbs most of the 1064nm IR light and re-lases it in visible 532nm green laser light. Then an IR filter (assuming it's a quality laser built properly) cleans out any remaining 1064nm and 808nm IR laser light that may have leaked through. Then it's focused by the final objective lens.
The 808nm pump diode is often as high as 1/2Watt - 500mW in power to push through all the crystals and filters, and compensate for all the transition losses in efficiency etc. This also makes green lasers more prone to getting very warm because the extra wattage and inefficiency all comes out as waste heat.
All these parts and steps make the green laser module very temperature sensitive. And the thermal expansion and contraction in the mounting assembly and the crystals themselves can greatly affect the efficiency, to the point it won't successfully lase through all the steps to produce green.