Related Experiment Video
Updated: Apr 22, 2026
12:19
Measurement of Quantum Interference in a Silicon Ring Resonator Photon Source
Published on: April 4, 2017
7.9K
Orbital angular momentum light frequency conversion and interference with quasi-phase matching crystals
Optics Express
|October 17, 2014
Summary
Researchers achieved second-harmonic generation of orbital angular momentum (OAM) light using quasi-phase matching crystals. This generated UV light with OAM, demonstrating OAM conservation and creating unique photonic gear structures for advanced measurements.
Area of Science:
- Quantum Optics and Photonics
- Nonlinear Optics
- Optical Communications
Background:
- Light with orbital angular momentum (OAM) is crucial for advanced optical applications like high-capacity communications and quantum information processing.
- Frequency conversion techniques are essential for expanding the usable frequency range of light.
- Quasi-phase matching (QPM) nonlinear crystals offer efficient frequency conversion with high nonlinear coefficients and no walk-off.
Purpose of the Study:
- To experimentally demonstrate second-harmonic generation (SHG) of OAM-carrying light using a QPM crystal.
- To verify the conservation of OAM during the frequency conversion process.
- To explore novel interference phenomena arising from OAM superposition in SHG.
Main Methods:
- Experimental second-harmonic generation (SHG) of light carrying orbital angular momentum (OAM) using a quasi-phase matching (QPM) nonlinear crystal.
- Utilized a specially designed interferometer to verify OAM conservation.
- Employed a pump beam with a superposition of opposite-sign OAM to observe interference patterns.
Main Results:
- Successfully generated UV light with a high orbital angular momentum (OAM) of 100 ℏ via SHG.
- Confirmed OAM conservation through experimental verification using a specialized interferometer.
- Observed unique photonic gear-like interference structures in the SHG light when using OAM superposition pump beams, providing direct evidence of OAM conservation.
Conclusions:
- The study presents the first experimental demonstration of SHG for OAM-carrying light using QPM crystals.
- The observed photonic gear structures serve as a sensitive indicator for OAM conservation, with potential applications in ultra-sensitive angular measurements.
- The developed theoretical framework and experimental methods are applicable to other nonlinear frequency conversion processes and can be extended to the quantum regime.
Related Concept Videos
01:11Atomic Nuclei: Larmor Precession Frequency
3.5K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
3.5K
02:18Interference and Diffraction
28.5K
Interference is a characteristic phenomenon exhibited by waves. When two electromagnetic waves interact with their peaks and troughs coinciding, a resulting wave with enhanced amplitude is produced. This is known as constructive interference. In this case, the two waves interacting are in phase with each other.
28.5K
01:30Atomic Emission Spectroscopy: Interference
778
In atomic emission spectroscopy (AES), high-temperature atomizers excite a broad range of elements and molecules that generate complex emissions from sources such as oxides, hydroxides, and flame combustion products in the flame or plasma. Several strategies can be employed to minimize spectral interferences caused by overlapping emission lines or bands. These include increasing instrument resolution, choosing alternative emission lines, optimally placing the detector in low-background regions,...
778
01:21Time and frequency -Domain Interpretation of Phase-lag Control
467
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...
467
01:25Atomic Absorption Spectroscopy: Interference
2.3K
Interference leads to systematic error in atomic absorption (AA) measurements by enhancing or diminishing the analytical signal or the background. These interferences can be grouped into three main categories: spectral interference, chemical interference, and physical interference.
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
Spectral interference occurs when signals from other elements or molecules overlap with the analyte signal, falsely elevating or masking the analyte's absorbance. This interference can be corrected using Zeeman,...
2.3K
01:24Time and frequency -Domain Interpretation of Phase-lead Control
561
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...
561