Effective reflectivity of hyperbolic microlenses.
We investigate the effective reflectivity of a hyperbolic microlens. At its position of peak coupling, this type of lens, which couples more power into a single-mode optical fiber than any other reported microlens, is found to reflect ~ -40 dB of the incident optical power back into a typical semiconductor laser. This reflectivity induces a peak-to-peak shift of 3.7 GHz in the lasing frequency of the 1.53-microm multiquantum-well distributed Bragg reflector laser that is tested. The addition of a two-layer dielectric coating diminishes the frequency shift by over an order of magnitude, which corresponds to a lens reflectivity of ~ -60 dB. A comparison is made with standard hemispheric microlenses.
Edwards
C A
CA
Presby
H M
HM
Stulz
L W
LW