Specifications

6 Chapter 2. First light
ItisassumedthataMOGLabsDLCcontrollerwillbeusedtodrive
thelaser. Ifanalternativesupplyisused,notethat+5Vmustbe
providedonpin15oftheheadboardconnectortoopentheprotective
relay. SeesectionB.1forconnectiondetails. Alsopleasereferto
the laser test data for the maximum safe operating current.
2.1 Temperature
Thepreferreddiodetemperaturewilldependonthediode,there-
quiredwavelength,andtheambientroomtemperature. Forexam-
ple,typicalAlGaAsdiodesusedfordatastorageapplications(CD-R
burners)haveanominalwavelengthofλ =784nmat25
◦
C,with
a dλ/dT slopeof −0.3nm/
◦
C, implyingan optimumtemperature of
about12
◦
. Dependingonthehumidity,lowtemperaturesmayin-
ducecondensation onthe diodeandcollimation lens.Thefilterwill
determine thefinal wavelength, andthe feedback isgenerally suffi-
cientto “pull”the wavelengthby±5nm, andthusin thisexamplea
sensible set temperature would be about 17 to 18
◦
C.