Laser Diode 취급 및 사용상 주의사항


8. The best heatsink material is copper, but aluminum is also a fair heat conductor.



9. If aluminum is used, the surface should not be anodized in the region where the laser


package makes contact with the heatsink. The aluminum oxide anodized coating makes an


effective thermal insulator.



10. The diode package should be attached to a heatsink plate at least several millimeters thick.



11. Thermal compound, or an indium foil washer can be used to reduce the thermal impedance


of this interface.



12. Finally, when testing out a heatsink configuration, it is wise to test the temperature drop


between the laser package and the heatsink using a very small thermocouple touched against


the base of the package. The temperature drop during laser operation should be only 1-2º C.




Open Laser Package Precautions




1. The C-mount package is a simple open heatsink, and there is no protection for the delicate


laser chip. The laser chip is very fragile and must be protected from any mechanical contact.


The exposed laser facets (mirror coatings) must not be contaminated with any foreign material.


Facet contamination can cause immediate and permanent damage to the laser. You should


not blow on the laser, or expose the laser to smoke, dust, oils, or adhesive fumes.



2. The laser facets are sensitive to accumulation of dust. When the laser is operating, dust


particles tend to be attracted to the laser facet. As the dust particles enter the intense optical


field at the laser facet, they burn, and the residues accumulate in the laser facet. Unless the


laser is operated in a true "class 100" clean-room environment, this dust accumulation will


occur, even in a seemingly clean "lab environment". This kind of contamination does not occur


very rapidly, but over several hundred hours of operation in a normal room environment, tiny


"specks" will appear on the laser facet under microscopic examination. These will gradually


degrade the laser prematurely. If the C-mount laser is to be operated outside of a clean-room for


more than short periods. it should be packaged within a sealed container to prevent this dust


accumulation. This does not require a true hermetic sealing of the laser. An epoxy seal or o-ring


seal around the laser assembly is prefectly sufficient.