Optimal binary gratings for multi-wavelength magneto-optical traps

Area of Science:

• Quantum optics
• Atomic physics
• Nanophotonics

Background:

• Grating magneto-optical traps are crucial for portable quantum metrology using ultracold atoms.
• Designing single optics for multi-wavelength laser cooling (e.g., for Sr or Yb atoms) presents challenges due to wavelength-dependent diffraction.
• Efficient loading of atoms into optical lattice or tweezer clocks requires precise control over laser parameters.

Purpose of the Study:

• To develop a simplified model for predicting the diffraction efficiency of binary gratings across various wavelengths.
• To provide an empirical fit for grating design parameters, avoiding complex 3D simulations.
• To enable informed design of gratings for multi-wavelength applications in quantum technologies.

Main Methods:

• Optical characterization of diverse binary gratings at multiple wavelengths.
• Development of an empirical model correlating grating diffraction efficiency with dimensionless etch depth, period, and duty cycle.
• Experimental validation of the model against measured diffraction data.

Main Results:

• A simple empirical fit accurately models grating diffraction efficiency for a broad parameter range.
• The model achieves accuracy within a few percent, simplifying grating design.
• The developed model is applicable to gratings optimized for two or more wavelengths.

Conclusions:

• Informed design of multi-wavelength gratings is now feasible for advanced quantum technologies.
• This work facilitates the development of portable metrological devices utilizing ultracold atoms.
• The empirical model streamlines the engineering of optical components for atomic clocks and related quantum systems.