Theoretical Prediction of Fiber Coupling for Ellipsoidal Microlens

Abstract

A theoretical approach for an optical lens tip on a single-mode fiber end to improve power coupling from laser diode is presented in this work. The lens shape considered here is an ellipsoid. Based on scalar diffraction and Gaussian mode shapes for the laser and fiber fields, a theoretical model is developed to predict the coupling performance of this microlens. Theoretically, both a high coupling efficiency up to 77% and a large alignment tolerance for 10% off-peak are achieved. The proposed method facilitates mass production to achieve a high-yield and high-coupling efficiency that is suitable to be used in the commercial fiber transmission industry.

Semiellipsoid microlens fabrication method using UV proximity printing

“…The thickness of UV-curing glue is about 20-30 μm, which is thin enough to neglect geometric effects. The coordinate defined [6] for the present theoretical analysis from LD to optical fiber with a semiellipsoid microlens can be simplified and shown in Fig. 6.…”

“…The ellipsoid shape of microlens with variable radii may have the effect of improving the wave front matching between the propagating laser beam and the fiber model [5]. Chao et al [6] achieved a high optical coupling efficiency between an SMF and an edge-emitting LD using a semiellipsoid microlens on the SMF endface. The semiellipsoid microlens was fabricated using photolithography, incomplete thermal reflow, mold electroforming, and polydimethylsiloxane (PDMS) injection.…”

Hemi-ellipsoidal microlensed fiber based on polishing and polymer technology

“…Evolution and development in the field of fiber optic connectivity, in particular optical coupling end elements, is an essential requirement for improving power coupling efficiency between optoelectronic devices, especially laser diodes and optical fibers. The use of Single-Mode Fiber (SMF), in general, has led to the need for the integration of interconnection devices that meet requirements for optimal optical transfer rates of signal in fiber-optic communication systems [1]. The optical beam emitted by a laser diode (LD), being of asymmetrical section, whereas a SMF has a circular geometric section, leads to a low coupling efficiency for high ellipticity laser beams [2].…”

Fabrication of microlens array with well-defined shape by spatially constrained thermal reflow

“…In recent years, microlens arrays (MLAs) have been widely used in optical communication systems and optical signal processing systems, such as optical sensors [1], fiber coupling [2], photovoltaic cells [3], light diffusers [4] and 3D displays [5], etc. To fabricate MLAs with different requirements, various methods have been developed, including ultra-precision diamond cutting [6], two-photon direct laser writing [7], femtosecond laser wet etching [8], gray-scale mask lithography [9], surface manipulation by electrostatic field [10] and thermal reflow [11], etc.…”