Broadband spontaneous parametric downconversion in reconfigurable poled linearly uncoupled resonators

Area of Science:

• Quantum Optics
• Nonlinear Optics
• Photonics

Background:

• Spontaneous parametric downconversion (SPDC) is a key process for generating photon pairs.
• Efficient SPDC typically requires dispersion engineering, especially in doubly resonant systems.
• Single resonators have limitations in bandwidth for photon-pair generation.

Purpose of the Study:

• To theoretically investigate SPDC in a novel periodically poled structure.
• To demonstrate efficient, reconfigurable, and broadband photon-pair generation.
• To explore the potential of this device for various infrared bands.

Main Methods:

• Theoretical study of SPDC in a coupled resonator system.
• Utilizing a Mach-Zehnder interferometer for nonlinear coupling.
• Modeling SPDC in periodically poled lithium niobate (PPLN) at 775 nm pump wavelength.

Main Results:

• Achieved efficient doubly resonant SPDC without dispersion engineering.
• Calculated high pair generation rates: up to 250 MHz/mW for single resonance.
• Demonstrated integrated rates up to 100 THz/mW over 170 nm bandwidth.
• Showcased reconfigurable generation over a 300 nm bandwidth (S, C, L, U bands).

Conclusions:

• The proposed coupled resonator structure offers a new pathway for broadband SPDC.
• The device's reconfigurability and efficiency are significant advantages over single resonators.
• This technology is compatible with existing platforms and suitable for diverse infrared applications.