Focusing single-order diffraction transmission grating with a focusing plane perpendicular to the grating surface

Area of Science:

• Optics and Photonics
• Diffraction Gratings
• Diffractive Optics

Background:

• Traditional transmission gratings (TG) lack focusing capabilities.
• Gabor zone plates (GZP) offer focusing but can suffer from higher-order diffraction.
• Combining different optical elements can lead to novel functionalities.

Purpose of the Study:

• To propose and theoretically investigate a novel focusing single-order diffraction transmission grating (FSDTG).
• To combine the dispersion properties of quasi-sinusoidal single-order diffraction transmission gratings (QSTG) with the focusing properties of annulus-sector-shaped-element binary Gabor zone plates (ASZP).
• To demonstrate the suppression of higher-order diffraction components and analyze focal properties.

Main Methods:

• Theoretical design of the FSDTG by integrating QSTG and ASZP principles.
• Numerical simulations using Fresnel-Kirchhoff diffraction to analyze diffraction patterns.
• Theoretical estimations to determine focal depth and resolving power based on structural parameters.

Main Results:

• The FSDTG exhibits a focusing plane perpendicular to the grating surface, unlike normal TGs.
• Higher-order diffraction components and harmonics are effectively suppressed.
• Focal depth and resolving power are found to be controllable via the FSDTG's structural parameters.

Conclusions:

• The proposed FSDTG successfully integrates focusing and single-order diffraction properties.
• The FSDTG offers enhanced control over diffraction characteristics, including focal properties and harmonic suppression.
• This novel diffractive optical element holds potential for advanced optical system designs.