Global fitting equation for constant-loss inverted taper.

Area of Science:

• Optoelectronics and Photonics
• Waveguide Optics
• Nanophotonics

Background:

• Inverted taper couplers are crucial components in integrated optical circuits.
• Designing constant-loss tapers requires precise control over waveguide geometry.
• Existing design methods can be complex and computationally intensive.

Purpose of the Study:

• To develop a simplified and accurate method for designing constant-loss inverted tapers.
• To establish an empirical equation for predicting taper geometry based on material properties and dimensions.
• To explore the use of normalized effective index for taper device characterization.

Main Methods:

• Utilized the Lagrangian approach for inverted taper coupler design.
• Calculated constant-loss inverted taper geometries for rectangular waveguides.
• Simulated a range of core refractive indices (3.0-3.6), cladding refractive indices (1.0-1.6), and waveguide thicknesses (200-300 nm).
• Introduced a novel approach based on the normalized effective index.

Main Results:

• Derived an empirical equation that accurately describes the geometry of simulated constant-loss inverted tapers.
• Demonstrated the effectiveness of the normalized effective index in characterizing taper devices.
• Validated the design approach across a wide parameter space.

Conclusions:

• The proposed method offers a significant advancement in the design of constant-loss inverted tapers.
• The empirical equation provides a practical tool for engineers and researchers in integrated optics.
• This work simplifies the design process for essential optoelectronic components.