An all fiber-based approach to generating special optical beams, called Bessel beams, could open up new applications in imaging, optical trapping and communications. Bessel beams look quite different from the usual Gaussian light beams found in optics. In particular, they possess several interesting properties including self-healing, diffraction-free propagation and the ability to carry orbital angular momentum (OAM). This family of beams—also known as vortex beams with a characteristic ring-like shape and a dark central region—include different "orders" of beams carrying different values of OAM.

esearchers have developed a new method for flexibly creating various needle-shaped laser beams. These long, narrow beams can be used to improve optical coherence tomography (OCT), a noninvasive and versatile imaging tool that is used for scientific research and various types of clinical diagnoses. "Needle-shaped laser beams can effectively extend the depth-of-focus of an OCT system, improving the lateral resolution, signal-to-noise ratio, contrast and image quality over a long depth range," said research team leader Adam de la Zerda from Stanford University School of Medicine. "However, before now, implementing a specific needle-shaped beam has been difficult due to the lack ...

Microplastic pollution is known to negatively impact seed germination and seedling growth. Although some studies have demonstrated the effects of microplastics on seed germination, the impact of microplastics on the internal biological activity of seeds remained unknown. Now, a group of researchers has used biospeckle optical coherence tomography to reveal that microplastics significantly hinder the internal activity in lentil seeds during germination and can lead to stunted growth at later stages.

Understanding the effects of microgravity on the human body is essential in enabling astronauts to travel through the harsh environment of space for months, or even years. Significant changes to the body's skeletal and muscle systems have been studied for decades, and strategies to maintain physical fitness are being applied through various countermeasures, including vigorous exercise, aboard the International Space Station. But scientists and researchers still have a lot to learn—including how time spent in space affects the eyes and brain.

Worldwide, as many as 285 million people suffer from serious eye diseases or blindness. Unfortunately, most of them do not have access to modern methods of treatment, so help often comes too late. This situation could change with the advent of a very significant improvement to a diagnostic tool that has been utilized for three decades for detecting ocular pathology—Optical Coherence Tomography (OCT).

Providing light with tailored properties through ultrafast supercontinuum generation represents an active field of nonlinear science research. A German-Australian research collaboration has presented a new concept that includes a longitudinally varying thickness nano-films in microstructured exposed core fibers. This offers low input energy, broadband and spectrally flattened spectra in the near infrared with high pulse-to-pulse stability, establishing a novel class of light sources for fields such as biophotonics, medical diagnostics, environmental sciences, or metrology.

In optics, when a collection of nonlinear processes act together on a pump beam, the resulting spectral broadening of the original pump beam gives rise to a supercontinuum . Supercontinuum sources for optical coherence tomography are of great interest since they provide a broad bandwidth for high resolution and high-power imaging sensitivity. For commercial fiber-based supercontinuum systems, researchers use high pump powers to generate a broad bandwidth and customized optical filters to modulate the spectra. In a new report now published on Science Advances , Xingchen Ji and a research team in electrical engineering, biomedical engineering and applied physics at the Columbia ...

Optical coherence tomography (OCT) is a non-invasive imaging method that can provide 3D information of biological samples. The first generation of OCT systems were based on time-domain imaging, using a mechanical scanning set-up. However, the relatively slow data acquisition speed of these earlier time-domain OCT systems partially limited their use for imaging live specimen. The introduction of the spectral-domain OCT techniques with higher sensitivity has contributed to a dramatic increase in imaging speed and quality. OCT is now widely used in diagnostic medicine, for example in ophthalmology, to noninvasively obtain detailed 3D images of the retina and underlying tissue structure.

Images provide information—what we can observe with our own eyes enables us to understand. Constantly expanding the field of perception into dimensions that are initially hidden from the naked eye, drives science forward. Today, increasingly powerful microscopes let us see into the cells and tissues of living organisms, into the world of microorganisms as well as into inanimate nature. But even the best microscopes have their limits. "To be able to observe structures and processes down to the nanoscale level and below, we need new methods and technologies," says Dr. Silvio Fuchs from the Institute of Optics and Quantum ...

Researchers have shown that entangled photons can be used to improve the penetration depth of optical coherence tomography (OCT) in highly scattering materials. The method represents a way to perform OCT with mid-infrared wavelengths and could be useful for non-destructive testing and analysis of materials such as ceramics and paint samples.

One of the challenges in optical imaging is to visualize the inside of tissue in high resolution. Traditional methods allow researchers to look to a depth of approximately 1 millimeter. Researchers at Delft University of Technology have now developed a new method that can penetrate up to four times as deep, up to around 4 millimeters. The healthcare sector in particular may benefit from the new technique in the future. The new imaging method brings together a number of existing techniques. The most important of these is optical coherence tomography , a technique ophthalmologists use to image the retina. OCT is ...

Optical coherence tomography offers astounding opportunities to image the complex structure of living tissue but lacks functional information. We present dynamic full-field optical coherence tomography as a technique to noninvasively image living human induced pluripotent stem cell (hiPSC)-derived retinal organoids. Colored images with an endogenous contrast linked to organelle motility are generated, with submicrometer spatial resolution and millisecond temporal resolution, creating a way to identify specific cell types in living tissue via their dynamic profile.

How a valveless embryonic heart tube pumps blood is a long-standing scientific mystery. Thanks to innovations in light-based technology, fresh insights are now available into the biomechanics of mammalian cardiogenesis—and in particular, the pumping dynamics of the mammalian tubular embryonic heart.

If the eyes are the mirror of the soul, then thanks to the translucent corneas, we can look deep into that soul. And thanks to the work of scientists from the Institute of Physical Chemistry of the Polish Academy of Sciences, we can look into the depths of the cornea itself. And that without touching it. All thanks to the introduction of an innovative method of holographic optical tomography.

Researchers have developed a new strategy that uses optical coherence tomography (OCT) to acquire both the surface and underlying details of impressionist style oil paintings. This information can be used to create detailed 3-D reconstructions to enhance the viewing experience and offer a way for the visually impaired to experience paintings.

A diagnostic workhorse, optical coherence tomography (OCT), provides high-resolution 3-D imaging of subsurface tissue structures. Most likely, for your last eye exam, the ophthalmologist took cross-sectional pictures of your dilated eyes to measure the thickness of your retinal layers using OCT

A new imaging technique developed by Biwei Yin and interdisciplinary researchers at the Massachusetts General Hospital and Harvard Medical School in the U.S., provides resolution at the subcellular-level to image the heart's vascular system. As a result, heart researchers can study and diagnose human coronary artery disease with greater precision. Conventionally, cardiologists employ intravascular optical coherence tomography (OCT) to assess the buildup of coronary plaque, which can narrow arteries to cause coronary artery disease.

Scientists in Christine Hendon's and Michal Lipson's research groups at Columbia University, New York, have used a microchip to map the back of the eye for disease diagnosis. The interference technology, like bat sonar but using light instead of sound waves , used in the microchip has been around for a little while. This is the first time that technical obstacles have been overcome to fabricate a miniature device able to capture high quality images. Ophthalmologists' current optical coherence tomography (OCT) devices and surveyors' light detection and ranging (LIDAR) machines are bulky and expensive. There is a push for ...

It is estimated that in 2015, 217 million people had moderate to severe vision impairment, while 36 million were blind, according to an article in the journal The Lancet Global Health. The World Health Organization predicts that about 80 % of vision impairment globally is preventable or curable. Early diagnosis is crucial for effective interventions.

Researchers in Sweden have developed cheaper, lighter and more efficient lidar technology that could pave the way for smaller autonomous craft such as drones and robots, and help enable better profitability in the vehicle industry. For autonomous vehicles, lidar is an essential technology to recognize and detect surrounding objects. A team at KTH Royal Institute of Technology has taken aim at the key component of lidar, optical beam-stearing, and developed a device that is significantly cheaper to manufacture, lighter and more resource-efficient than previous variations of the technology. Carlos Errando-Herranz, a postdoc at KTH's 's Division of Micro and ...

Radar technologies were originally designed to identify and track airborne military targets. Today they're more often used to detect motor vehicles, weather formations and geological terrain. Until now, scientists have believed that radar accuracy and resolution are related to the range of frequencies or radio bandwidth used by the devices. But a new Tel Aviv University study finds that an approach inspired by optical coherence tomography (OCT) requires little to no bandwidth to accurately create a high-resolution map of a radar's surrounding environment. "We've demonstrated a different type of ranging system that possesses superior range resolution and ...

Optical coherence tomography (OCT) is a light-based imaging technique currently used in clinical diagnostics to examine organs in vivo. The technique uses interferometry ; in which light reflected from an examined object combines with reference light that does not encounter the object to generate interference patterns that form 2-D and 3-D OCT images. It is possible to use longer wavelengths of light in the imaging technique for deeper penetration in light scattering materials. Such features offer possibilities for OCT in non-destructive testing (NDT) of samples, and improved non-invasive biomedical imaging. In a recent study, Niels M. Israelsen and co-workers at the ...

Researchers have developed a faster way to acquire 3-D endoscopic optical coherence tomography (OCT) images. With further development, the new approach could be useful for early detection and classification of a wide range of diseases. The new method uses computational approaches that create a full 3-D image from incomplete data. In the Optical Society journal Applied Optics , the researchers report that useful 3-D images could be constructed using 40 percent less data than traditional 3-D OCT approaches, which would decrease imaging time by 40 percent. OCT is a biomedical imaging technique that has seen expanding clinical use in recent years ...

A cheap, compact technique for analyzing samples at infrared wavelengths using visible-wavelength components could revolutionize medical and material testing. Infrared spectroscopy is used for material analysis, in forensics and in the identification of historical artifacts, for example,—but scanners are bulky and expensive. Visible- wavelength technology is cheap and accessible in items such as smartphone cameras and laser pointers. This led Leonid Krivitsky and colleagues at the A*STAR Data Storage Institute to develop a method in which a laser beam was converted into two linked lower energy beams: The link between the two beams allowed experiments using one beam ...