Mark J. Bloemer

Bio: Mark J. Bloemer is an academic researcher from United States Department of the Army. The author has contributed to research in topics: Photonic crystal & Second-harmonic generation. The author has an hindex of 38, co-authored 172 publications receiving 6707 citations. Previous affiliations of Mark J. Bloemer include Sapienza University of Rome.

The photonic band edge laser: A new approach to gain enhancement

Abstract: Near the band edge of a one‐dimensional photonic band gap structure the photon group velocity approaches zero. This effect implies an exceedingly long optical path length in the structure. If an active medium is present, the optical path length increase near the photonic band edge can lead to a better than fourfold enhancement of gain. This new effect has important applications to vertical‐cavity surface‐emitting lasers.

Optical limiting and switching of ultrashort pulses in nonlinear photonic band gap materials.

Abstract: We numerically investigate nonlinear propagation of ultrashort pulses in a one-dimensional photonic band gap structure. We find that, near the band edge, nonlinear effects cause a dynamical shift in the location of the band gap. We demonstrate that this nonlinear mechanism can induce intensity-dependent pulse transmission and reflections. In addition, pulse reshaping and pulse generation is observed. This phenomenon has important new applications in both optical limiting and optical switching.

Transparent, metallo-dielectric, one-dimensional, photonic band-gap structures

Abstract: We investigate numerically the properties of metallo-dielectric, one-dimensional, photonic band-gap structures. Our theory predicts that interference effects give rise to a new transparent metallic structure that permits the transmission of light over a tunable range of frequencies, for example, the ultraviolet, the visible, or the infrared wavelength range. The structure can be designed to block ultraviolet light, transmit in the visible range, and reflect all other electromagnetic waves of lower frequencies, from infrared to microwaves and beyond. The transparent metallic structure is composed of a stack of alternating layers of a metal and a dielectric material, such that the complex index of refraction alternates between a high and a low value. The structure remains transparent even if the total amount of metal is increased to hundreds of skin depths in net thickness.

Pulsed second-harmonic generation in nonlinear, one-dimensional, periodic structures

Abstract: We present a numerical study of second-harmonic (SH) generation in a one-dimensional, generic, photonic band-gap material that is doped with a nonlinear ${\ensuremath{\chi}}^{(2)}$ medium. We show that a 20-period, 12-\ensuremath{\mu}m structure can generate short SH pulses (similar in duration to pump pulses) whose energy and power levels may be 2--3 orders of magnitude larger than the energy and power levels produced by an equivalent length of a phase-matched, bulk medium. This phenomenon comes about as a result of the combination of high electromagnetic mode density of states, low group velocity, and spatial phase locking of the fields near the photonic band edge. The structure is designed so that the pump pulse is tuned near the first-order photonic band edge, and the SH signal is generated near the band edge of the second-order gap. This maximizes the density of available field modes for both the pump and SH field. Our results show that the ${\ensuremath{\chi}}^{(2)}$ response is effectively enhanced by several orders of magnitude. Therefore, mm- or cm-long, quasi-phase-matched devices could be replaced by these simple layered structures of only a few micrometers in length. This has important applications to high-energy lasers, Raman-type sources, and frequency up- and down-conversion schemes.

Dispersive properties of finite, one-dimensional photonic band gap structures : applications to nonlinear quadratic interactions

Abstract: We discuss the linear dispersive properties of finite one-dimensional photonic band-gap structures. We introduce the concept of a complex effective index for structures of finite length, derived from a generalized dispersion equation that identically satisfies the Kramers-Kronig relations. We then address the conditions necessary for optimal, phase-matched, resonant second harmonic generation. The combination of enhanced density of modes, field localization, and exact phase matching near the band edge conspire to yield conversion efficiencies orders of magnitude higher than quasi-phase-matched structures of similar lengths. We also discuss an unusual and interesting effect: counterpropagating waves can simultaneously travel with different phase velocities, pointing to the existence of two dispersion relations for structures of finite length.

Spectral properties and relaxation dynamics of surface plasmon electronic oscillations in gold and silver nanodots and nanorods

Abstract: The field of nanoparticle research has drawn much attention in the past decade as a result of the search for new materials. Size confinement results in new electronic and optical properties, possibly suitable for many electronic and optoelectronic applications. A characteristic feature of noble metal nanoparticles is the strong color of their colloidal solutions, which is caused by the surface plasmon absorption. This article describes our studies of the properties of the surface plasmon absorption in metal nanoparticles that range in size between 10 and 100 nm. The effects of size, shape, and composition on the plasmon absorption maximum and its bandwidth are discussed. Furthermore, the optical response of the surface plasmon absorption due to excitation with femtosecond laser pulses allowed us to follow the electron dynamics (electron−electron and electron−phonon scattering) in these metal nanoparticles. It is found that the electron−phonon relaxation processes in nanoparticles, which are smaller than t...

Photonic crystals

Abstract: The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

Parity–time-symmetric whispering-gallery microcavities

Abstract: It is now shown that coupled optical microcavities bear all the hallmarks of parity–time symmetry; that is, the system’s dynamics are unchanged by both time-reversal and mirror transformations. The resonant nature of microcavities results in unusual effects not seen in previous photonic analogues of parity–time-symmetric systems: for example, light travelling in one direction is resonantly enhanced but there are no resonance peaks going the other way.

Developing optofluidic technology through the fusion of microfluidics and optics

Abstract: We describe devices in which optics and fluidics are used synergistically to synthesize novel functionalities. Fluidic replacement or modification leads to reconfigurable optical systems, whereas the implementation of optics through the microfluidic toolkit gives highly compact and integrated devices. We categorize optofluidics according to three broad categories of interactions: fluid–solid interfaces, purely fluidic interfaces and colloidal suspensions. We describe examples of optofluidic devices in each category.

Transparent Conducting Oxides

Abstract: In the interim between the conception of this issue of MRS Bulletin on transparent conducting oxides (TCOs) and its publication, the remarkable applications dependent on these materials have continued to make sweeping strides. These include the advent of larger flat-screen high-definition televisions (HDTVs), larger and higher-resolution screens on portable computers, the increasing importance of low emissivity (“low-e”) and electrochromic windows, a significant increase in the manufacturing of thin-film photovoltaics (PV), and a plethora of new hand-held and smart devices, all with smart displays.1-7 Coupled with the increased importance of TCO materials to these application technologies has been a renaissance over the last two years in the science of these materials. This has included new n-type materials, the synthesis of true p-type materials, and the theoretical prediction and subsequent confirmation of the applicability of codoping to produce p-type ZnO. Considering that over the last 20 years much of the work on TCOs was empirical and focused on ZnO and variants of InxSn1-xO2, it is quite remarkable how this field has exploded. This may be a function of not only the need to achieve higher performance levels for these devices, but also of the increasing importance of transition-metal-based oxides in electro-optical devices. This issue of MRS Bulletin is thus well timed to provide an overview of this rapidly expanding area. Included are articles that cover the industrial perspective, new n-type materials, new p-type materials, novel deposition methods, and approaches to developing both an improved basic understanding of the materials themselves as well as models capable of predicting performance limits.