Progress in metal-insulator-metal waveguide lasers at near-infrared wavelengths

Strong light con¯nement can be achieved in metallic cavities which can con¯ne light to volumes with dimensions considerably smaller than the wavelength of light. It was commonly believed, however, that the high losses in metals are prohibitive for laser peration in metallic nano-cavities. Recently we have reported lasing in a metallic nano-cavity ¯lled with an electrically pumped semiconductor. Importantly, the manufacturing approach employed for these devices permits even greater miniaturization of semiconductor lasers. Furthermore, the approach allows for complex device shapes and the guiding of light between devices. Of particular interest are the metal-insulator-metal (MIM) waveguides. These MIM waveguides can propagate a transverse magnetic (TM0) mode which permits true deep sub-wavelength guiding of light in two dimensions. The manufacturing process is adapted to produce a variant of MIM waveguides. The presentation will look at the modeling, fabrication and operation of these devices. An overview will also be given of latest results from devices. Previously reported devices observed light that leaked out of the metallic nano cavity through the device base. This is not optimal as the lasing light travels transversally between the metal sidewalls of the pillar structure. Ideally, the transverse propagating mode needs to be coupled directly out to either a conventional dielectric waveguide or free space. We will discuss our progress in making metallic cavity nano lasers with coupling of the transverse propagating mode directly to free space, and present results from our latest attempts

Nano Lasers in Photonic VLSI

We examine the use of micro and nano lasers to form digital photonic VLSI building blocks. Problems such as isolation and cascading of building blocks are addressed, and the potential of future nano lasers explored

Metal coated DBR/DFB lasers

Metallic nano-cavities can be used to fabricate lasers of sub-wavelength dimensions. Currently, these lasers emit their light through the substrate. This complicates measurements of these devices and their integration in optical systems. Side-emission offers a way to circumvent these problems. We plan to implement side-emission via distributed feedback; this allows accurate tuning of a cavity’s resonant wavelength and its emissive properties. In this paper we will give an update of the work that has been done

Metal coated DBR/DFB lasers

Metallic nano-cavities can be used to fabricate lasers of sub-wavelength dimensions. Currently, these lasers emit their light through the substrate. This complicates measurements of these devices and their integration in optical systems. Side-emission offers a way to circumvent these problems. We plan to implement side-emission via distributed feedback; this allows accurate tuning of a cavity’s resonant wavelength and its emissive properties. In this paper we will give an update of the work that has been done

Metallic DFB lasers

In this paper we present our latest results on the design, fabrication and characterization of metal coated DFB lasers. These devices are based on a specialform of the metal-insulator-metal waveguides, which support plasmon gap modes. The distributed feedback provides control over the laser ~ wavelength and its emissive properties. The size of the semiconductor core can be as small as 100 nm, which is well below the d~ffraction limit of light. The devices operate in the near-infrared and may eventually be suitablefor low-power, high-speed applications

Metallic DFB lasers

In this paper we present our latest results on the design, fabrication and characterization of metal coated DFB lasers. These devices are based on a specialform of the metal-insulator-metal waveguides, which support plasmon gap modes. The distributed feedback provides control over the laser ~ wavelength and its emissive properties. The size of the semiconductor core can be as small as 100 nm, which is well below the d~ffraction limit of light. The devices operate in the near-infrared and may eventually be suitablefor low-power, high-speed applications

All-optical flip-flop based on coupled laser diodes

An all-optical set-reset flip-flop is presented that is based on two coupled lasers with separate cavities and lasing at different wavelengths. The lasers are coupled so that lasing in one of the lasers quenches lasing in the other laser. The flip-flop state is determined by the laser that is currently lasing. A rate-equation based model for the flip-flop is developed and used to obtain steady-state characteristics. Important properties of the system, such as the minimum coupling between lasers and the optical power required for switching, are derived from the model. These properties are primarily dependent on the laser mirror reflectivity, the inter-laser coupling, and the power emitted from one of the component lasers, affording the designer great control over the flip-flop properties. The flip-flop is experimentally demonstrated with two lasers constructed from identical semiconductor optical amplifiers (SOAs) and fiber Bragg gratings of different wavelengths. Good agreement between the theory and experiment is obtained. Furthermore, switching over a wide range of input wavelengths is shown; however, increased switching power is required for wavelengths far from the SOA gain peak

Electromagnetic Dissociation of Nuclei in Heavy-Ion Collisions

Large discrepancies have been observed between measured Electromagnetic Dissociation(ED) cross sections and the predictions of the semiclassical Weiz\"acker-Williams-Fermi(WWF) method. In this paper, the validity of the semiclassical approximation is examined. The total cross section for electromagnetic excitation of a nuclear target by a spinless projectile is calculated in first Born approximation, neglecting recoil. The final result is expressed in terms of correlation functions and convoluted densities in configuration space. The result agrees with the WWF approximation to leading order(unretarded electric dipole approximation), but the method allows an analytic evaluation of the cutoff, which is determined by the details of the electric dipole transition charge density. Using the Goldhaber-Teller model of that density, and uniform charge densities for both projectile and target, the cutoff is determined for the total cross section in the nonrelativistic limit, and found to be smaller than values currently used for ED calculations. In addition, cross sections are calculated using a phenomenological momentum space cutoff designed to model final state interactions. For moderate projectile energies, the calculated ED cross section is found to be smaller than the semiclassical result, in qualitative agreement with experiment.Comment: 28 page

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