Overcoming the Diffraction Limit on the Size of Dielectric Resonators Using an Amplifying Medium

Area of Science:

• Optics and Photonics
• Nanotechnology
• Laser Physics

Background:

• Current subwavelength resonator fabrication relies on negative permittivity plasmonics or high refractive index dielectrics.
• These methods have limitations in achieving ultra-small resonator sizes.

Purpose of the Study:

• To introduce an alternative method for subwavelength resonator creation.
• To demonstrate the feasibility of subwavelength dielectric lasers.

Main Methods:

• Modification of dielectric resonator modes using an active medium.
• Analysis of phase shifts in a subwavelength dielectric active layer.
• Demonstration of an unconventional mode with zero round-trip phase shift.

Main Results:

• An unconventional mode is formed in subwavelength dielectric resonators with sufficient optical gain.
• This mode allows for a zero net phase shift after light propagation and reflection.
• A laser significantly smaller than the wavelength of generated light was designed.

Conclusions:

• The proposed method offers a novel pathway to subwavelength dielectric lasers.
• Laser size is inversely proportional to the square of the active medium's refractive index.
• This research paves the way for fabricating subwavelength-sized dielectric lasers.