Ageing tests of VCSELs in non-hermetic 85/85 condition Ageing tests of VCSELs in non-hermetic 85/85 condition S. Hou, 2014/08/26 Academia Sinica

2 Sample preparation −VCSELs of various manufacturers Die/Wire bonds by FOCI robot VCSEL dies on an 10×10 cm 2 PCB −TOSA of TrueLight assembled on PCB, no latch assembly

3 Bare Die VCSEL, forward bias uniformity −Multimeter P/N voltage

4 DC light power measurements −V-I-L scan by a LabView setup VCSELs covered by a large (10 × 10 mm 2 ) GaAs PIN, Mechanical alignment is required NI 6024E PCMCIA to an XP notebook −Power meter measurement

5 DC bias to VCSELS −DC bias by Agilent E3631A, Keithley 2304A current kept at ~ 5 mA/ch −Bias at 1.65 V, 1.75 V, 2.0 V, to VCSELs channel current measured, bundled.

6 DC bias current uniformity

7 85/85 chamber −Temperature stable at 0.1 o C −Humidity stable at 0.2% RH −Cooled to 30/55 before opening, to prevent condensation Burn periods conducted 30/50 : 118 hrs 85/85 : 12 hrs 85/85 : 94 hrs 85/85 : 275 hrs 85/85 : 316 hrs 85/85 : 363 hrs Continuing..

8 Reference samples −Not in oven, to examine the systematics of DAQ −Join afterwards, DAQ with test samples 1F45 1F59 1F58

9 Reference samples −Not in oven, to examine the systematics of DAQ −Join afterwards, DAQ with test samples 1F45 1F59 1F58

10 Reference samples −FINISAR Gb −board 2, two 4x1 arrays VCSELS are not centered at PIN Mechanical alignment is an issue

11 TOSA samples are robust in 85/85 TrueLight TOSA 1F Gb 1F58 10 Gb 1F59 10 Gb No obvious loss After ~700 hr 85/85 Bad electric contact Boards were poorly prepared, ch8 light recovered 1F45 1F58 1F59

12 Oxide 000, 008, 051 degradation TSD-000, after 10 ch lost 6, after ~400 85/85 ch closer to PIN center near PIN edge Not sure what cause degradation,, For channels near PIN center could be the PIN geometrical Not observed in other brands

13 Oxide 000, 008, 051 degradation TSD-008, after 10 ch lost 2, after ~ /85 ch closer to PIN center near PIN edge

14 Oxide 000, 008, 051 degradation TSD-051, after 10 ch lost 2, after ~ /85 ch closer to PIN center near PIN edge

15 Non-hermetic 751 degradation TSD-751, lost one ch in bonding? one more in early test? Total loss of 10 chs after /50 Very fragile Could ther be other damage mechanism?

16 Oclaro degradation Oclaro, badly degraded after /50 ch closer to PIN center near PIN edge

17 FINISAR array degradation Only 1 of 8, showing large degradation, the rest are consistent with small degradation, in /85

18 Avago degradation All 10 are consistent with small degradation, in /85 ch closer to PIN center near PIN edge