Advanced linear axial wavelength spreading through cascaded double hyperchromats

Area of Science:

• Optics and Photonics
• Optical Engineering

Background:

• Achieving linear axial spectral decomposition with low chromatic aberration is a persistent challenge in optical system design.
• Conventional optical systems often struggle with axial chromatic spreading, limiting performance in various applications.

Purpose of the Study:

• To design and optimize cascaded double-hyperchromatic optical systems (2x2 lenses) for highly linear axial spectral decomposition.
• To investigate both purely refractive and hybrid refractive-diffractive configurations to achieve extremely low equivalent Abbe numbers.

Main Methods:

• Exploration of lens configurations, including alternating focal length signs in purely refractive systems.
• Analysis of diffractive optical element (DOE) placement and focal length selection in hybrid systems.
• Optimization of systems to minimize equivalent Abbe numbers for enhanced spectral decomposition.

Main Results:

• Optimized purely refractive systems achieved absolute equivalent Abbe numbers of 0.983.
• Optimized hybrid systems demonstrated absolute equivalent Abbe numbers as low as 0.65, over four times lower than single diffractive elements.
• Systems using standard materials showed significantly low equivalent Abbe numbers (2.5 for refractive, 1.4 for hybrid).

Conclusions:

• Cascaded double-hyperchromatic systems offer a viable solution for achieving linear axial spectral decomposition with minimal chromatic aberration.
• Hybrid refractive-diffractive systems show particular promise for achieving ultra-low equivalent Abbe numbers.
• These advancements hold potential for improving a wide range of optical applications limited by axial chromatic spreading.