Laser diode to single-mode circular core dispersion-shifted/dispersion-flattened fiber excitation via hyperbolic microlens on the fiber tip: Prediction of coupling efficiency by ABCD matrix formalism

A 2 µm Gallium Antimonide Semiconductor Laser Based on Slanted, Wedge-Shaped Microlens Fiber Coupling

“…Microlens fiber coupling involves the direct processing or attachment of a specific microlens to the end face of the fiber [10], enabling direct coupling with the semiconductor laser. The microlens shape can typically be conical [11], hyperbolic [12], parabolic [13], cylindrical [14], and more. This paper utilizes the microlens fiber coupling method, directly coupling the microlens fiber with the light source.…”

“…In 2010, Yang et al from Yishou University, Taiwan, compared the coupling efficiencies of tapered hyperbolic microlens fibers and tapered hemispherical microlens fibers and found that tapered hyperbolic microlens have much higher coupling efficiencies [15]. In 2014, Das from India studied the coupling efficiency of hyperbolic microlens fibers at two different wavelengths, 1.3 µm and 1.5 µm, using the ABCD matrix and obtained a higher coupling efficiency at 1.3 µm [12]. In 2015, Sanker at the Cape Institute of Technology, India, used a new type of fiber with an inverted-taper microlens at the fiber tip in order to maximize the coupling efficiency between a semiconductor laser and a single-mode fiber [16].…”