Related Experiment Video
Updated: Feb 2, 2026
08:21
Wideband Optical Detector of Ultrasound for Medical Imaging Applications
Published on: May 11, 2014
11.7K
Ultrasound vibration measurements based on laser optical feedback imaging.
Applied Optics
|November 22, 2018
Summary
This study demonstrates nanometric ultrasound vibration detection using laser optical feedback imaging (LOFI). The LOFI setup effectively detects ultra-high frequencies, even with low-power lasers and standard detection noise levels.
Area of Science:
- Optics
- Acoustics
- Materials Science
Background:
- Laser optical feedback imaging (LOFI) is a technique used for various sensing applications.
- Detecting ultrasound vibrations with nanometric amplitude presents significant challenges due to noise and frequency limitations.
Purpose of the Study:
- To investigate the capability of a LOFI setup for detecting nanometric amplitude ultrasound vibrations.
- To analyze the impact of noise dynamics on vibration detection.
- To demonstrate the detection of ultra-high frequencies and transient vibrations.
Main Methods:
- Numerical simulations were employed to model ultrasound vibrations with different temporal shapes (harmonic and transient).
- The study considered laser quantum noise dynamics and detection noise separately.
- Experimental validation was performed by detecting ultrasound vibrations in water at the air/water interface.
Main Results:
- Simulated vibration noise showed good agreement with theoretical predictions.
- Ultra-high frequencies (gigahertz range) were successfully detected using a low-power laser and conventional detection.
- A method for reducing noise in short transient vibrations by reconstructing their wide vibration spectrum was presented.
Conclusions:
- The LOFI setup is a viable method for detecting nanometric ultrasound vibrations, including ultra-high frequencies.
- The technique is robust against typical laser and detection noise.
- Experimental results confirm the simulation findings for transient-harmonic ultrasound vibrations.
Related Concept Videos
00:46Feedback Inhibition
57.1K
Biochemical reactions are occurring constantly in cells, converting starting substances to different products, usually with the help of enzymes that speed the reactions. Without enzymes, it would take far too long for most reactions to occur to be useful to the cell!
57.1K
01:01Feedback Loops
64.4K
In most cases, excessive hormone production is prevented by negative feedback—a loop that starts with a stimulus inducing the release of a particular substance, like a hormone, to maintain a certain level before triggering a signal that results in a decrease in further release of the hormone.
64.4K
01:19Vibrating Concrete
401
Mechanical vibrators are instrumental in compacting newly poured concrete within formwork and around reinforcements. This process is essential to eliminate trapped air pockets and establish a dense concrete mass. One widely used method is vibrating by internal vibrators, often referred to as a poker vibrator or immersion vibrator. It is rapidly inserted through the full depth of the freshly laid concrete and slightly extends into the layer below it (which remains in a plastic state). Consistent...
401
01:24Effects of feedback
1.0K
Feedback in control systems plays a critical role in shaping various operational parameters, extending beyond simple error reduction to influence stability, bandwidth, gain, impedance, and sensitivity. Understanding these effects requires examining a basic feedback system characterized by defined input, output, error, and feedback signals.
Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents...
Feedback significantly modifies the gain of a control system. The gain of a system without feedback is altered by a factor of one plus GH, where G represents...
1.0K
01:26Feedback control systems
722
Feedback control systems are categorized in various ways based on their design, analysis, and signal types.
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
Linear feedback systems are theoretical models that simplify analysis and design. These systems operate under the principle that their output is directly proportional to their input within certain ranges. For instance, an amplifier in a control system behaves linearly as long as the input signal remains within a specific range. However, most physical systems exhibit inherent nonlinearity...
722
01:24Facial Feedback Hypothesis
663
Charles Darwin proposed that facial expressions are an evolutionary adaptation for communication. He argued that these expressions are not influenced by culture but are universal across species. For example, a snarling expression with exposed teeth signals a threat in many animals, including humans. Darwin also suggested that displaying an emotion can intensify the feeling. Smiling, for example, could enhance one's sense of happiness. This idea laid the foundation for understanding the role...
663