For Buried Heterostructure(BH) Quantum Well LASER fabricated on Indium Phosphide (InP) substrate the effective refractive index is about 3.48 from Fabry-Perot (FP) Measurement i had performed earlier. The as cleaved mirrors on this type of lasers has reflectivity of about 0.3 which was confirmed from the calculations using data obtained from FP measurements.
To reduce the reflectivity of the facet, anti-reflection coating was sputtered on the facet using Nordiko 2000 physical vapour deposition (PVD) machine.The devices used were 1mm long edge emmiting LASERS lasing wavelength at 1550nm. The results showed the improvement of external quantum differential efficiency. This allows the determination of internal losses on the device.
These are exciting results which can be used to measure internal losses and determine internal quantum differential efficiency as function of change in reflectivity of as cleaved facets. (I am expecting to write a paper on gain measurements on these devices using this technique am developing).
You can read my paper published on IEEE, titled Thermal Performance of 1.55μm InGaAlAs Quantum Well Buried Heterostructure Lasers which talks about efficiencies and losses of these devices.
No comments:
Post a Comment