HL7851G GaAlAs Laser Diode Description The HL7851G is a high power 0.78 µm band GaAlAs laser diode with a multi-quantum well (MQW) structure. It is suitable as a light source for optical disk memories, levelers and various other types of optical equipment. Hermetic sealing of the package assures high reliability. Features • • • • Visible light output: λp = 785 nm Typ Small beam ellipticity: 9.5:23 High output power: 50 mW (CW) Built-in monitor photodiode 173 HL7851G Absolute Maximum Ratings (TC = 25°C) Item Symbol Rated Value Unit Optical output power PO 50 mW 1 Pulse optical output power PO (pulse) 60* LD reverse voltage VR (LD) 2 V PD reverse voltage VR (PD) 30 V Operating temperature Topr –10 to +60 °C Storage temperature Tstg –40 to +85 °C Note: mW 1. Maximum 50% duty cycle, maximum 1 µs pulse width Optical and Electrical Characteristics (TC = 25°C) Item Symbol Min Typ Max Unit Test Conditions Optical output power PO 50 — — mW Kink free Threshold current Ith — 45 70 mA Slope efficiency η 0.35 0.55 0.7 mW/mA 40 mW/ I (45 mW) – I (5 mW) Operating current Iop — 140 170 mA PO = 50 mW LD Operating voltage Vop — 2.3 2.7 V PO = 50 mW Lasing wavelength λp 775 785 795 nm PO = 50 mW Beam divergence (parallel) θ// 8 9.5 12 deg. PO = 50 mW, FWHM Beam divergence (perpendicular) θ⊥ 18 23 28 deg. PO = 50 mW, FWHM Monitor current Is 25 — 150 µA PO = 5 mW, VR (PD) = 5 V Astigmatism AS — 5 — µm PO = 5 mW, NA = 0.4 174 HL7851G Typical Characteristic Curves 175 HL7851G Typical Characteristic Curves (cont) 176