Fiber Optic Sensors favors better in photoacoustic microscopy

Fiber Optic Sensors in photoacoustic microscopyA Chinese team of researchers has created a new twist on fiber optic sensors. It promotes the development of a smart flexible photoacoustic imaging technique, which is regarded as a way to enlarge new applications in portable devices, instrumentation, and medical diagnostics.

The operation of the new ultrasound sensor is based on fiber lasers that rely on fiber optic technology to manufacture fiber sensors for photoacoustic imaging. To be more precise, these fiber laser systems apply fiber optic ultrasound determination, utilizing the acoustic effects on laser beam pulses via the thermoelastic effect (temperature changes).

The thing is that traditional fiber optic sensors trace very weak signals due to their high sensitivity via phase measurement. Herewith, this type of fiber sensor can be employed for military purposes to find low-frequency (kilohertz) acoustic waves. Nevertheless, they provide weak operation for “ultrasound waves at the megahertz frequencies used for medical applications because ultrasound waves usually propagate as spherical waves and have a very limited interaction length with optical fibers”.

It should be noted that the main application of the novel fiber sensors is medical imaging, herein, they offer better sensitivity than the piezoelectric transducers in use today. Components of a special ultrasound fiber optic sensor include a portable fiber laser set in the 8-micron-diameter core of a single-mode optical fiber. The standard length of the fiber optic system is only 8 millimeters.

The team uses two highly reflective fiber Bragg grating mirrors written into the fiber core to achieve optical feedback to manufacture the fiber laser. Then they dope the optical fiber with ytterbium and erbium to result in efficient optical gain at 1,530 nanometers. Additionally, a 980-nanometer semiconductor laser operates as the pump laser.

The applications of such fiber laser systems with a kilohertz-order linewidth (the width of the optical spectrum) can include their use as fiber sensors, so they provide a high signal-to-noise ratio. Also, ultrasound detection takes advantage of the combined methods because side-incident ultrasound waves spoil the optical fiber, modulating the laser beam frequency.

The fiber optic sensors based on fiber lasers are highly promising for application in photoacoustic microscopy. The team applies a 532-nm nanosecond pulsed laser to illuminate a sample and excite ultrasound signals leading to a photoacoustic image of the vessels and capillaries. Moreover, it is possible to use the fiber optic system for structural imaging of other tissues and functional imaging of oxygen distribution by employing other excitation wavelengths.

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

Fiber optic sensors detect sleep apnea syndrome

FBG sensors for sleep apnea detectionSleep apnea syndrome is regarded as a risk factor for traffic accidents because it leads to excessive daytime sleepiness. A fiber optic sensor based on optical fibers for sleep apnea syndrome has been tested in a clinical application varying in age from 13 to 78 years. Such a fiber sensor is perfect for preliminary sleep apnea syndrome screening because its respiratory disturbance index corresponds well with the apnea-hypopnea index.

The promising application of such fiber optic sensors includes a screening of patients suffered from the SAS during standard sleep at home. Moreover, the process of downsizing the optical fiber sensors results in the connection between PSG and pulse oximetry. The fiber sensor can be used to examine sleep apnea syndrome in children (2 – 12 years) providing improved pediatric analysis.

It should be noted that the novel fiber optic technology provides more accurate SAS results compared to the traditional sensing system. Additionally, the developed optical fiber sensor is considered to be non-invasive and non-restrictive, also it is quiet and compact, therefore, it is highly useful for the process of SAS screening during conventional sleep at home.

Fiber optic sensors provide a promising application for screening latent patients who suffered from sleep apnea syndrome during normal sleep. Optical fibers in such sensing systems are narrower and wider within several centimeters. Researchers use commercially affordable optical fibers for SAS screening. The operating principle of fiber sensors is based on the measurement of the deviation of output optical power from an optical fiber sheet by micro-bending loss and/or bending loss.

Significant benefits of fiber optic sensing systems include no need for a patient to use any specific clothing or devices because the measurement results are transmitted to a remote place for further analysis and diagnosis. “The deviation in the output optical fiber power from the POF sheet due to micro-bending loss and/or bending loss caused by the lateral pressure change created by the motion of the person’s chest during respiration is measured.”

Also, the researchers have designed a multi-channel fiber optic sensor and applied it in a hotel, full medical check-up, and clinical test in pediatrics. The fiber optic sensing system demonstrated 38/42 42 examinees had  Pro-AHI > 5 and were suspected of sleep apnea syndrome. The fiber sensor has a compact size by it having only 15.3% of the volume of a standard sensing system that allows detecting sleep apnea syndrome. The obtained results show that the fiber optic system is perfect for preliminary SAS screening and monitoring of the respiration and heartbeat of neonates. 

Optromix is a manufacturer of innovative fiber optic products for the global market. The company provides the most technologically advanced fiber optic solutions for clients. Optromix produces a wide range of fiber optic devices, including cutting-edge customized fiber optic Bragg grating product line and fiber Bragg grating sensor systems. Moreover, Optromix is a top choice among the manufacturers of fiber Bragg grating monitoring systems. If you have any questions, please contact us at info@optromix.com

Tapered optical fibers change the future of laser system processing

Nowadays new fiber laser technology allows transmitting multikilowatt power, ultrashort pulse durations, repetition rates up to 1 GHz, and high laser beam quality in a compact version. The thing is that the ultrafast laser system with pulse durations in the femtosecond and picosecond range is widely used in numerous industrial processes. 

Benefits of these fiber lasers provided high-quality, virtually athermal materials processing combining with developments in fiber laser technology, process development, laser beam handling, and delivery, enlarge fields for many advanced scientific and industrial applications. Nevertheless, tapered optical fibers provide high laser beam power with perfect beam features in a space-effective format, herewith, at not expensive production costs that are slightly more than traditional optical fibers.

Thus, these ultrafast fiber laser systems offer fast industrial performance by transmitting fast investment returns from high processing speed and accuracy. It should be noted that the rapid rise in output laser beam power due to rare-earth-doped optical fiber allows designing new fiber optic systems with perfect performance (high laser beam quality, overall efficiency, and flexibility in operating wavelength and radiation format).

The thing is that current fiber optic technologies promote creating new configurations as well, however, the cost of solid-state gain material is high, combined with thermal management challenges cause crucial obstacles to its widespread application. The popularity of pulsed laser systems increases every day. Solid-state, disk, and fiber lasers are considered to be the most potential versions for high-average-power generation, herein, fiber laser systems are in advance.

Compared to solid-state and disk laser systems, fiber lasers provide such advantages as compactness, robustness, efficiency, ease of thermal management, and reliable laser beam quality. Additionally, fiber laser systems have greatly lower production and maintenance costs beneficial for pico- and femtosecond high-repetition-rate kilowatt-level laser beam development. Modern high-average-power fiber lasers usually apply chirped-pulse amplification.

Nevertheless, even amplifiers based on fiber optic technology can provoke very high optical peak intensities leading to detrimental nonlinear laser beam pulse distortion or even destruction of the gain medium or other optical fiber elements. Moreover, there are various nonlinear effects (self-phase modulation, stimulated Raman scattering, mode instabilities, and poor output laser beam quality) that increase in pulsed high-power laser systems limiting their performance. The promising solution is the increase in the core diameter of the optical fiber.

Optromix is a fast-growing fiber laser manufacturer and a vendor of optical fiber sensors and optical monitoring systems. The company offers fast turnkey solutions and creates sophisticated fiber laser systems for special purposes. Optromix uses only its technologies and develops a broad variety of fiber lasers. If you have any questions or would like to buy a laser system, please contact us at info@optromix.com