What the study found
The study reports a tabletop interferometer that measures the radiation force exerted by light. It uses a thin metallic cantilever, a capacitance bridge, and a high-power pulsed laser to detect very small force-driven motion.
Why the authors say this matters
The authors say the experiment uses equipment commonly found in an undergraduate physics and electronics teaching laboratory. They also state that it provides insight into electromagnetic wave theory, low-noise circuit design, and Fourier analysis.
What the researchers tested
The researchers built a mechanical cantilever-based interferometer on a tabletop. A high-power pulsed laser beam, about 1 W, was used to excite oscillations in a thin metallic cantilever that formed a parallel-plate capacitor with a printed circuit board trace.
What worked and what didn't
Using a capacitance bridge geometry, the team measured capacitance changes on the order of femtofarads. These changes were induced by radiation forces of a few nano-newtons, according to the abstract.
What to keep in mind
The abstract does not describe comparison experiments, measurement error, or limits on accuracy. It also does not state how broadly the approach applies beyond this tabletop laboratory setup.
Key points
- A tabletop interferometer was used to measure the force of light.
- A thin metallic cantilever was driven by a high-power pulsed laser beam.
- The setup detected capacitance changes on the order of femtofarads.
- The abstract says the measured radiation forces were a few nano-newtons.
- The authors say the experiment uses equipment common in undergraduate teaching laboratories.
Disclosure
- Research title:
- Capacitance bridge interferometer measures light-induced radiation force
- Authors:
- Devashish Shah, Pradumn Kumar, P. Sarin
- Institutions:
- Indian Institute of Technology Bombay, Indian Institute of Technology Bombay, Indian Institute of Technology Bombay
- Publication date:
- 2026-04-22
- DOI:
- 10.1119/5.0232550
- OpenAlex record:
- View
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