K. Ding

Record performance of electrical injection sub-wavelength metallic-cavity semiconductor lasers at room temperature

We demonstrate a continuous wave (CW) sub-wavelength metallic-cavity semiconductor laser with electrical injection at room temperature (RT). Our metal-cavity laser with a cavity volume of 0.67λ3 (λ = 1591 nm) shows a linewidth of 0.5 nm at RT, which corresponds to a Q-value of 3182 compared to 235 of the cavity Q, the highest Q under lasing condition for RT CW operation of any sub-wavelength metallic-cavity laser. Such record performance provides convincing evidences of the feasibility of RT CW sub-wavelength metallic-cavity lasers, thus opening a wide range of practical possibilities of novel nanophotonic devices based on metal-semiconductor structures.

Fabrication challenges of electrical injection metallic cavity semiconductor nanolasers

The recently emerged metallic-cavity nanolasers have opened a new phase of miniaturization of semiconductor lasers down to sub-wavelength scale. This new type of semiconductor lasers is suitable for many low-power applications due to its small size, tight optical confinement and good heat dissipation. However, there are major technical challenges in the fabrication of such nanolasers that must be overcome to make high-quality devices with high yield needed for practical applications. Here we will discuss several fabrication issues that are critical to the device performance. These issues, including device patterning, pillar etching, surface passivation and metal deposition, will determine both optical and electrical properties, especially the lifetime, threshold, and efficiency of a nanolaser.

Trap-state whispering-gallery mode lasing from high-quality tin-doped CdS whiskers

High-quality surface tin-doped hexagonal CdS whiskers were synthesized by a well-controlled in situ source exchange chemical vapor deposition route. Under local light excitation, the detected microphotoluminescence from any positions along the length of these whiskers exhibits strong and multi-mode trap-state whispering-gallery (WG) mode emission. With elevating the pumping power, some of these WG modes start lasing at an ultra-low threshold, with lasing wavelength covering a broad range from ∼540 to ∼750 nm. Calculations using a plane-wave model of WG modes show that all these trap-state lasing modes are transverse magnetic polarized, which was well explained by a two-dimensional finite element simulation. The surface doped semiconductor structures have potential applications as low-threshold tunable micro/nanoscale lasers in optical storage, lighting, and optical communications.High-quality surface tin-doped hexagonal CdS whiskers were synthesized by a well-controlled in situ source exchange chemical vapor deposition route. Under local light excitation, the detected microphotoluminescence from any positions along the length of these whiskers exhibits strong and multi-mode trap-state whispering-gallery (WG) mode emission. With elevating the pumping power, some of these WG modes start lasing at an ultra-low threshold, with lasing wavelength covering a broad range from ∼540 to ∼750 nm. Calculations using a plane-wave model of WG modes show that all these trap-state lasing modes are transverse magnetic polarized, which was well explained by a two-dimensional finite element simulation. The surface doped semiconductor structures have potential applications as low-threshold tunable micro/nanoscale lasers in optical storage, lighting, and optical communications.

Unambiguous demonstration of room temperature CW operation of a sub-wavelength metallic cavity laser

We demonstrated room temperature CW operation in a sub-wavelength metallic-cavity laser under electric injection with record performance. The lasing linewidth down to 0.5 nm is about one eighth of the previously reported value.

CW operation of a subwavelength metal-semiconductor nanolaser at record high temperature under electrical injection

We report on high temperature (240K) CW operation of a metal-semiconductor nanolaser under electrical injection. The nanolaser confines light within subwavelength scale in one direction with a physical volume smaller than one wavelength cubic.

Semiconductor Nanolasers (A Tutorial)

This tutorial focuses on miniaturization of semiconductor lasers down to sub-micron scale based on both bottom-approach such as nanowires and nanosheets and top-down approach such as etched nano-pillars encased in metallic or plasmonic shells.

Recent progress in metallic cavity nanolasers of subwavelength sizes

This talk will review the most recent progress on metallic cavity nanolasers with sub-wavelength size cavities, especially the efforts towards the first demonstration of CW operation at room temperature under electrical injection.

Semiconductor-metal core-shell plasmonic nanolasers: Recent experimental results

We systematically characterized semiconductor-metal core-shell plasmonic nanolasers of various sizes and shapes under electrical injection. New experimental results will be presented including detailed temperature-dependent and duty cycle dependent performance measurements, as well as polarization measurements.

Semiconductor-metal core-shell plasmonic nanolasers with a bowtie antenna cross section

A new plasmonic bowtie nanolaser structure is fabricated where a semiconductor gain core is enclosed by a metal shell with bowtie cross section built-in. Light emission characteristics under electrical injection will be reported.

Semiconductor plasmonic nanolasers

We present recent results on modeling, fabrication, and characterization of semiconductor nanolasers based on semiconductor-metal core-shell waveguides. In particular, results of lasers with a sub-diffraction-limit thickness will be presented under electrical injection.