Highly efficient light emission at lambda = 1.5 microm by a three-dimensional tungsten photonic crystal.

Area of Science:

• Photonics
• Materials Science
• Solid-State Physics

Background:

• Photonic crystals offer unique light manipulation properties.
• Tungsten is a refractory metal with potential for high-temperature applications.
• Efficient light emission in the infrared spectrum is crucial for various technologies.

Purpose of the Study:

• To demonstrate, for the first time, effective light emission from a three-dimensional tungsten photonic crystal.
• To characterize the emission properties, including wavelength, bandwidth, optical power, and conversion efficiency.
• To investigate the role of the photonic band structure in enabling this emission.

Main Methods:

• Fabrication of a three-dimensional tungsten photonic crystal.
• Electrical biasing of the photonic crystal to induce thermal emission.
• Spectroscopic analysis to measure emission wavelength and bandwidth (full width at half-maximum).
• Measurement of emitted optical power and electrical-to-optical conversion efficiency.

Main Results:

• Effective light emission achieved at a wavelength (lambda) of 1.5 micrometers.
• Thermal emission with a narrow full width at half-maximum (delta lambda) of 0.85 micrometers at 7 V bias.
• High emitted optical power of 4.5 W per emitting surface.
• Electrical-to-optical conversion efficiency of approximately 22% per emitting surface.
• Emission is attributed to a large, absolute infrared bandgap and specific photonic dispersion characteristics.

Conclusions:

• A 3D tungsten photonic crystal can efficiently emit infrared light.
• The demonstrated device exhibits promising performance metrics for photonic applications.
• The underlying photonic band structure is key to achieving this efficient and narrow-band emission.