Related Experiment Video
Updated: May 25, 2026
06:30
Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition
Published on: August 29, 2017
Controllable coherent perfect absorption in a composite film
Shourya Dutta-Gupta1, O J F Martin, S Dutta Gupta
1Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
Optics Express
|January 26, 2012
Summary
Metal-dielectric composites enable controllable coherent perfect absorption (CPA) and anti-lasing. Researchers found absorption is key for CPA and demonstrated tunable CPA frequencies, enhancing anti-laser flexibility.
Area of Science:
- Metamaterials and Nanophotonics
- Condensed Matter Physics
- Wave Phenomena
Background:
- Coherent perfect absorption (CPA) is a phenomenon where incident light is completely absorbed by a medium.
- Anti-lasing utilizes CPA principles to suppress light emission.
- Metal-dielectric composites offer tunable optical properties for advanced photonic applications.
Purpose of the Study:
- To demonstrate controllable coherent perfect absorption (CPA) and anti-lasing using metal-dielectric composites.
- To investigate the conditions and system parameters influencing CPA.
- To explore the tunability of CPA frequency in heterogeneous media.
Main Methods:
- Theoretical investigation of light interaction with a heterogeneous medium composed of metal-dielectric composites.
- Numerical calculations analyzing the conditions for CPA under bidirectional illumination.
- Systematic study of parameter dependence, including absorption and dispersion effects.
Main Results:
- Demonstrated that metal-dielectric composites can achieve controllable CPA and anti-lasing.
- Established absorption as a fundamental requirement for achieving CPA.
- Showcased the ability to tune the CPA frequency to two distinct frequencies, even with dispersion present.
Conclusions:
- Metal-dielectric composites provide a versatile platform for controlling light absorption and emission.
- The findings offer enhanced flexibility in the design and realization of anti-lasers.
- This work deepens the understanding of CPA mechanisms and their practical implications.
Related Concept Videos
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
01:05Absorption of Radiation
The rate of heat transfer by emitted radiation is described by the Stefan-Boltzmann law of radiation:
01:26Phase Contrast and Differential Interference Contrast Microscopy
Phase-Contrast Microscopes
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
01:10Control Systems
Control systems are everywhere in contemporary society, influencing diverse applications from aerospace to automated manufacturing. These systems can be found naturally within biological processes, such as blood sugar regulation and heart rate adjustment in response to stress, as well as in man-made systems like elevators and automated vehicles. A control system is essentially a network of subsystems and processes that collaboratively convert specific inputs into desired outputs.
At the heart...
At the heart...
01:05Total Internal Reflection Fluorescence Microscopy
Total internal reflection fluorescence microscopy or TIRF is an advanced microscopic technique used to visualize fluorophores in samples close to a solid surface with a higher refractive index, such as a glass coverslip. TIRF only allows fluorophores in proximity to the solid surface to be excited. When light from a medium with a lower refractive index (such as air) hits the glass coverslip at a critical angle, the light undergoes total internal reflection stead of passing through the glass.
01:21IR Absorption Frequency: Hybridization
Hydrocarbons such as alkanes, alkenes, and alkynes show characteristic C–H stretching absorption bands. These IR stretching frequencies depend on the hybridization of the involved carbon atom and can be explained in terms of the s character of each hybridized atomic orbital.
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...
Among the sp, sp2, and sp3 hybridized orbitals, sp orbitals have the maximum s character (50%). Consequently, the electrons are held more closely to the nucleus, resulting in stronger and shorter C–H bonds that stretch at a...