Related Experiment Video
Updated: May 5, 2026
07:56
A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
9.8K
Overlapping multimode interference couplers as a building block for folded interferometric circuits
Optics Express
|May 4, 2026
Summary
Researchers combined multiple multimode interference couplers (MMIs) into one device. This integrated device reduces power loss and improves performance in optical modulators.
Area of Science:
- Photonics
- Integrated optics
- Optical devices
Background:
- Standard multimode interference couplers (MMIs) rely on input/output symmetry for splitting.
- Spatial overlap of multiple MMI functions within a single cavity is challenging.
Purpose of the Study:
- To demonstrate spatial overlapping of independent MMI functions.
- To design and experimentally validate a combined MMI (Co-MMI) device.
- To apply the Co-MMI in a Mach-Zehnder modulator for improved performance.
Main Methods:
- Designing a 4x4 Co-MMI on an Indium Phosphide (InP) platform.
- Integrating two 50/50 splitters within a single multimode cavity.
- Implementing the Co-MMI in a double-pass Mach-Zehnder modulator configuration.
Main Results:
- Achieved low imbalance and low leakage in the Co-MMI.
- Demonstrated successful spatial overlap of two 50/50 MMI splitters.
- Obtained over 50% reduction in Vπ (half-wave voltage) for the modulator.
- Improved the extinction ratio of the Mach-Zehnder modulator.
Conclusions:
- Spatial overlapping of MMI functions is feasible.
- The Co-MMI offers a compact and efficient solution for integrated photonic circuits.
- The Co-MMI enhances the performance of Mach-Zehnder modulators.
Related Concept Videos
02:18Interference and Diffraction
28.7K
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.
28.7K
01:07Interference and Superposition of Waves
5.8K
When two waves of the same nature occur in the same region simultaneously, they result in interference. Interference of waves implies that the net effect of the waves is the sum of the individual waves' effects. However, it does not imply that the individual waves affect the propagation of other waves.
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
Interference occurs in mechanical waves, such as sound waves, waves on a string, and surface water waves. Mechanical waves correspond to the physical displacement of particles. Hence,...
5.8K
01:20Design Example: Capacitance Multiplier Circuit
1.9K
In integrated circuit technology, a capacitance multiplier is often utilized to produce a larger capacitance value when a small physical capacitance falls short. This is achieved by a circuit that multiplies capacitance values by a factor of up to 1000, such that a 10-pF capacitor can replicate the performance of a 100-nF capacitor.
The circuit illustrated in Figure 1 below incorporates two op-amps, with the first operating as a voltage follower and the second acting as an inverting amplifier.
The circuit illustrated in Figure 1 below incorporates two op-amps, with the first operating as a voltage follower and the second acting as an inverting amplifier.
1.9K
01:26Phase Contrast and Differential Interference Contrast Microscopy
9.4K
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...
9.4K
01:21Impedance Combination
919
Consider a string of christmas lights, each bulb symbolizing an impedance element. In this series configuration, the flow of electric current remains uniform across every component. This behavior aligns with Kirchhoff's Voltage Law (KVL), which asserts that the total impedance in such a setup equals the sum of individual impedances—akin to resistors in series. It follows that the voltage from the power source is distributed proportionally among these components, adhering to the voltage...
919
01:10Interference: Path Lengths
2.5K
Consider two sources of sound, that may or may not be in phase, emitting waves at a single frequency, and consider the frequencies to be the same.
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
Two special sources may be considered when they are in phase. This can be easily achieved by feeding the two sources from the same source. An example would be synchronizing the two speakers by feeding them with the same source, such as the sound waves produced by a tuning fork. This setup ensures that the two sources have the same frequency and are...
2.5K