Efficient Emission of Highly Polarized Thermal Radiation from a Suspended Aligned Carbon Nanotube Film.

A polarized light source covering a wide wavelength range is required in applications across diverse fields, including optical communication, photonics, spectroscopy, and imaging. For practical applications, high degrees of polarization and thermal performance are needed to ensure the stability of the radiation intensity and low energy consumption. Here, we achieved efficient emission of highly polarized and broadband thermal radiation from a suspended aligned carbon nanotube film.

High-Speed Modulation of Polarized Thermal Radiation from an On-Chip Aligned Carbon Nanotube Film.

Spectroscopic analysis with polarized light has been widely used to investigate molecular structure and material behavior. A broadband polarized light source that can be switched on and off at a high speed is indispensable for reading faint signals, but such a source has not been developed. Here, using aligned carbon nanotube (CNT) films, we have developed broadband thermal emitters of polarized infrared radiation with switching speeds of ≲20 MHz.

Microemitter-Based IR Spectroscopy and Imaging with Multilayer Graphene Thermal Emission.

IR analyses such as Fourier transform infrared spectroscopy (FTIR) are widely used in many fields; however, the performance of FTIR is limited by the slow speed (∼10 Hz), large footprint (∼ millimeter), and glass bulb structure of IR light sources. Herein, we present IR spectroscopy and imaging based on multilayer-graphene microemitters, which have distinct features: a planar structure, bright intensity, a small footprint (sub-μm), and high modulation speed of >50 kHz. We developed an IR analysis system based on the multilayer-graphene microemitter and performed IR absorption spectroscopy.

High-Speed and On-Chip Optical Switch Based on a Graphene Microheater.

Graphene is a promising material for producing optical devices because of its optical, electronic, thermal, and mechanical properties. Here, we demonstrated on-chip optical switches equipped with a graphene heater, which exhibited high modulation speed and efficiency. We designed the optimal structure of the optical switch with an add/drop-type racetrack resonator and two output waveguides (the through and drop ports) by the electromagnetic field calculation.

A light emitter based on practicable and mass-producible polycrystalline graphene patterned directly on silicon substrates from a solid-state carbon source.

We developed a procedure for direct patterning of graphene with arbitrary position, size, and shape on silicon substrates from a solid-state carbon source without dry etching processing. Our light emitting graphene devices perform on a par with those based on high crystallinity graphene obtained mechanical exfoliation or chemical vapor deposition.