An investigative study of efficient coupling mechanism of a hemispherical microlens tipped single mode photonic crystal fiber to a laser diode by ABCD matrix formulation and determination of the optimal separation distance

Photonic crystal fibers capable to operate endlessly in single moded regime offer varied and novel applications of practical interests. Hence, appropriate coupling with an optical source, working at wavelengths of well known significance is required for the effective functioning of these fibers. We present here an optical coupling scheme of such a single mode photonic crystal fiber with a laser diode through easily fabricable hemispherical microlens using ABCD matrix formulation. We, also, report the best distance of separation of the laser diode from photonic crystal fiber producing the maximum coupling. Our result should find wide use by system designers and engineers to appropriately calibrate photonic crystal fibers based on our formulation devoid of complexity of the deeply involved numerical method.