Related Experiment Video
Updated: Apr 18, 2026
09:04
Lens-free Video Microscopy for the Dynamic and Quantitative Analysis of Adherent Cell Culture
Published on: February 23, 2018
10.1K
Flat lens criterion by small-angle phase
Optics Express
|January 22, 2015
Summary
A new imaging criterion using small-angle phase can identify flat lenses and predict image locations for various systems. This method aids in designing novel flat lenses, including broadband and super-resolution capabilities.
Area of Science:
- Optics and Photonics
- Metamaterials and Nanophotonics
Background:
- Flat lenses offer potential for miniaturized optical systems.
- Characterizing flat lens imaging performance remains a challenge.
Purpose of the Study:
- To introduce a universal criterion for identifying and characterizing flat lenses.
- To predict the imaging capabilities of flat lenses based on their physical properties.
Main Methods:
- Analysis of the angular dependence of small-angle phase in planar, uniform media.
- Validation through full-wave simulations of various flat lens configurations.
Main Results:
- A classical imaging criterion based on small-angle phase reliably determines flat lens capability and image location.
- The criterion accurately predicts both far-field and near-field (super-resolved) image positions.
- New flat lens designs for transverse-electric polarization, broadband operation (UV-Vis), and extended image planes were predicted and simulated.
Conclusions:
- Small-angle phase is a versatile metric for categorizing and designing flat lenses.
- The proposed criterion simplifies the assessment of flat lens performance.
- This work opens avenues for advanced flat lens applications.
Related Concept Videos
01:16Focusing of Light in the Eye
7.8K
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...
7.8K
01:28Accuracy, limits, and approximation
1.4K
Accuracy, limits, and approximations are common in many fields, especially in engineering calculations. These concepts are imperative for ensuring that a given value is as close as possible to its true value.
Accuracy is defined as the closeness of the measured value to the true or actual value. In engineering mechanics, repeated measurements are taken during theoretical or experimental analyses to ensure that the result is precise and accurate.
The accuracy of any solution is based on the...
Accuracy is defined as the closeness of the measured value to the true or actual value. In engineering mechanics, repeated measurements are taken during theoretical or experimental analyses to ensure that the result is precise and accurate.
The accuracy of any solution is based on the...
1.4K
01:26Linearization and Approximation
213
Linearization is a mathematical technique used to approximate complex, nonlinear functions with simpler linear models in the vicinity of a chosen reference point. The method is based on the idea that, although a function may be difficult to evaluate exactly, its behavior near a specific input value can often be closely approximated by the tangent line at that point. This approach is particularly useful when small deviations from a known value are involved.Consider the square root function, for...
213
01:20The Phase Rule
130
The phase rule describes the relationship between the variance (degrees of freedom), the number of components, and the number of phases in a system at equilibrium.Variance is a concept that denotes the number of independent intensive properties (properties are those that do not depend on the amount of material in the system), such as temperature, pressure, and composition, that can be altered without impacting the number of phases in equilibrium.In a single-component system, such as pure water,...
130
01:21Time and frequency -Domain Interpretation of Phase-lag Control
453
Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
453
01:24Time and frequency -Domain Interpretation of Phase-lead Control
538
Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second.
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
538