Category Archives: Laser Research

Use of Lasers For Potential Treatment or Cure To Parkinson’s

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What is Parkinson’s Disease (PD) and how can it be cured? PD is defined as being a progressive disease of the nervous system that is marked by slow imprecise movements such as shaking and rigidity that worsen over time. This disease currently affects more than one million people within the US while an estimated eight million people are living with PD worldwide. These numbers don’t include the thousands of cases that go undetected. It is also found more often in those who are 50 years of age or older.

Many would say that the cause of PD is unknown or idiopathic however, as noted in a previous article published on MedGadget, researchers at Okinawa Institute of Science and Technology, JP and University of Otago, NZ have since determined that it can be associated with the “degeneration of the basal structure of the brain,” or the basal ganglia, “and a deficiency of the neurotransmitter dopamine”. This transmitter is a key transmitter within the central nervous system and is responsible for sending signals to and from brain neurons. Researchers have also found that dopamine is a key component when it comes to helping with the control of muscle movement. However, one dose of dopamine isn’t able to cure Parkinson’s because it would have to be injected over a certain period of time and at a controlled dosage.

The researchers at OIST and UO created a method of “encapsulating dopamine within liposomes that can then be released using a femtosecond (FS) laser”. Liposomes are fatty spherical structures or bubbles that are often artificially created in order to carry drugs or other substances into tissues as a means to treat cancer and other diseases. The substances within these liposomes only come into contact with outside cells and tissues when the liposomes have been ruptured by an external force. The researchers utilized an FS laser that was capable of cracking open the liposomes in order to release dopamine in precise dosages which were then determined by the length of time the laser had been activated.

This research is still being tested however the research team believes that this technology may eventually lead to medical implants that release encapsulated dopamine. The dopamine would then be activated by using a tiny laser thus replicating the same process of release found within the brain.

There are many ways to go about finding the cure or treatment for Parkinson’s and when it comes to laser technology there remains a wide array of options and techniques. Another group of researchers chose to focus on a completely different component. Researchers at Chalmers worked alongside researchers from Polish Wroclaw University of Technology in order to determine the exact cause of PD and which method best detects these causes.  Their results were both insightful and stunning.

They determined that properly functioning proteins can be damaged by toxic amyloid fibers or fibrils. After a prolonged period of time, damaged amyloid fibers start to function poorly thus taking a toll on the human body. These toxic fibers have also been linked to other diseases such as Alzheimer’s. The team’s results concluded that toxic amyloids would have to be targeted and removed by using lasers however these malfunctioning proteins and protein aggregates are currently being treated with chemicals which are highly toxic to the human body.

The research performed by those at Chalmers and PWUT provides opportunities for scientists to develop other optical techniques which enables current and future researchers to detect and study amyloid structures. For example, multi-photon laser technique can be used to distinguish the damaged proteins (protein aggregates) from the healthy ones by removing the protein aggregates thus curing the disease while malfunctioning proteins may be able to be detected through photoacoustic therapy or the use of laser light which delivers flash heating to specific tissue locations in order to destroy a specific target. Their research also suggests that new protein-based materials could be designed for specific applications within photonics and related fields.

While it is true that numerous other research teams believe that the cure for PD is through photo therapy (light therapy) which is the act of utilizing emitted light in the treatment of physical or mental illness for a prescribed period of time, we can still all agree on one thing: that the final cure to PD remains a mystery and that any treatment involving the use of lasers may just be the way to go.

For further information on the studies conducted by the researchers at Chalmers and PWUT visit Nature Photonics at: http://www.nature.com/nphoton/journal/v7/n12/full/nphoton.2013.282.html

 

Powering the Photon Factory in New Zealand

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If you have ever been to Auckland, New Zealand, you know the natural beauty of its surroundings and the vibrancy of the city. What you may not know is that the campus of the University of Auckland is home to a unique facility, one that uses the power of intense pulses of light to manipulate, measure and machine matter — it uses photons as its ‘machinery.’

The Photon Factory

This unexpected find is the result of the efforts of Dr. Cather Simpson, who joined the faculty of the University of Auckland in 2007. Soon after arriving, Dr. Simpson challenged herself to “bring the rich versatility of high-tech ultrashort laser pulses to New Zealand academic and industry innovators.” This challenge resulted in the creation of a facility dubbed the ‘Photon Factory.’ The Photon Factory fulfills multiple functions: it is a laboratory for education, research, innovation and even economic development.

The ‘Photon Factory’ at the University of Auckland (left) and Dr. Cather Simpson (right) along with members of her team of students, researchers & entrepreneurs

Dr. Simpson became familiar with ultrafast lasers and their extremely short pulses (on the order of 100 fs = 100 x 1015 seconds) while pursuing research in ultrafast energy conversion in molecules. She used them as a tool in her lab when she started her career as a professor at Case Western Reserve University (CWRU). Light can be converted by molecules into other forms of energy; by studying the dynamics of molecular complexes excited by light on femtosecond to microsecond timescales through both experiments and modeling, it is possible to learn how molecules direct the energy acquired in light absorption. The ultimate goal of these investigations is to understand how the structure and environment influence molecular functions so that photochemical and photophysical behavior can be both predicted and tailored.

Having achieved tenure at CWRU, she found the opportunity to move to New Zealand compelling, and there, her research has flourished to span from fundamental spectroscopy to applied device development. The Photon Factory is the facility and resource she has developed to accomplish her research goals and to bring the power of laser light to New Zealand, and beyond.

A Factory of Ideas & People, Powered by Light

How did the Photon Factory come into being? When Dr. Simpson moved to New Zealand, the country was undergoing a transformation in how academic research was being funded. A newly-formed government was in the process of making structural changes, closing the Ministry of Research, Science and Technology and moving some of its functions to a newly created agency, the Ministry of Business Innovation and Employment. This signaled the new government’s stance that science and technology were to be viewed as drivers of economic development. Because she arrived at this time and had no history with the previous methods of funding, Simpson was able to embrace and navigate the new system. She realized that the government wanted to use the academic community to fill a large gap in R&D spending that New Zealand companies were not filling — the level of spending on internal R&D was well below that of international companies, and nearly non-existent. She also realized that, unlike what she had encountered in America, funding sources would scrutinize how she engaged with industry and what type of business case there was for the proposed work as a key factor in whether her work would be funded or not. She began to pay attention to what companies were identifying as the problems they wanted to solve. But at the same time, she was eager to continue her ultrafast chemistry research.

Dr. Simpson recognized that the laser tools that she was using in chemistry were being used for other applications, some that might have more immediate use to industry. Her experience and interest in laser-matter interactions was a natural bridge into material processing applications. She also understood that there were challenges, such as slow machining speeds, that kept ultrashort pulsed machining from widespread use. With these ideas in mind, the multi-purpose, multi-user Photon Factory, was born.

Since its opening in 2010, the facility has grown to over 30 students and employees from physics, chemistry and engineering backgrounds who work on dozens of academic and commercial projects. These activities range from basic research stemming from Simpson’s chemistry background, such as evaluating the photobehavior of improved solar energy harvesting molecules, to more industry-friendly applied research, such as fabricating photomasks for microfluidic chip production.

The Photon Factory generates commercial contracts and grants, and also serves as a test bed for science innovation and a training ground for future scientists and engineers. Interactions with New Zealand-based companies including Next Window, Rakon, Fisher & Paykel, Izon and others have produced such wide-ranging results as improved touch-sensitive displays, better locking nuts, more efficient designs for solar thermal energy harvesting, and new designs for GPS chips. Global companies like Intuitive Surgical (based in Sunnyvale, CA) have brought projects to the Photon Factory to develop laser-based surgery in difficult tissue. Such projects have yielded patent filings, and an increased ability to understand commercial opportunities. They have also created conditions for both students and Dr. Simpson herself to get involved in industry-sponsored and spin-off technologies.

Entrepreneurship has become a buzzword in academic circles, but in New Zealand, the Photon Factory takes the concept to heart. Two spin-off companies have already been generated by the work of the Photon Factory. The first, Engender Technologies, Ltd., was established in 2011 as a result of taking a serious look at the challenges faced by New Zealand’s dairy industry. When approached by a venture capital firm with the five top problems in that sector, Dr. Simpson found one that seemed possible to address by photonics and then chose a team of students and engineers to find a solution. The problem she chose was that of improving sperm sorting by sex, to address the needs of dairy farmers who are turning to artificial insemination to control the numbers of bulls versus cows. The resulting microfluidic and photonic device is a huge departure from the state-of-the-art flow cytometry based solution, and one that could only be identified by people with a new set of tools at their disposal. A second spin-off is currently being formed to commercialize a new centrifugal microfluidic technology developed in the Photon Factory to analyze milk at “point of cow” in the milking shed. The new company already has backing from VC and other investors. It is probably no coincidence that both start-ups are addressing New Zealand’s important agricultural sector.

Cell-sorting prototype developed within the Photon Factory

Transforming Matter & Lives

So, what has the Photon Factory achieved thus far? Besides new chemical insights, material processing to solve diverse problems, and generating novel concepts and devices, it has turned Dr. Simpson into an entrepreneur and led her to tackle questions that she previously would not have envisioned. Her passion for research has been applied to significant problems in diverse application areas, from touch sensor displays to challenges in dairy farming. And perhaps most importantly, this passion has been applied to developing future engineers and scientists with deep curiosity and an entrepreneurial spirit. All of these things have resulted from the fortuitous confluence of a researcher, with a specialized high-tech tool, finding interesting challenges and opportunities based on New Zealand’s desire to develop more innovation to drive economic growth. Who knew that photons could be so powerful?

For more information, or to reach Dr. Cather Simpson, visit www.photonfactory.auckland.ac.nz/en.html

The Laser’s Founding Father: Remembering Charles H. Townes

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By Geoff Giordano

Photo of Charles Townes with a ruby maser amplifier courtesy of Bell Labs

In his 1999 book How the Laser Happened, the late Charles Hard Townes explained that, “Once invented, lasers found a myriad of uses” and noted that they had advanced to the point that “the smallest lasers are so tiny one cannot see them without a microscope.”

A far cry from the heady days of the 1950s. Imagine Townes conceiving and building a maser (microwave amplification by stimulated emission of radiation) at Columbia University before the heated race to pursue a patent for an optical maser — the laser. Imagine the fevered discussion in the scientific community as Townes and Arthur Schawlow at Bell Labs beat Gordon Gould and Technical Research Group to that first laser patent — two months before Theodore Maiman built his ruby laser for Hughes Research Laboratories in Malibu, CA, in 1960.

Patent, filed in 1958

 

Townes — who famously conceived the idea for the laser while sitting on a park bench in Washington, DC in 1951 — worked until his 99th year, maintaining an office at the physics department of the University of California, Berkeley. The campus honored him with a birthday celebration July 28, 2014; he passed away in January 2015. Continue reading →

Arizona State Researchers Demonstrate White Lasers, Which Could Revolutionize Everyday Lighting

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Researchers at Arizona State University have created white laser light with an array of semiconductor lasers in a compact arrangement. The project helps pave the way toward better lighting and light-based wireless communication, as white lasers are more luminous and energy efficient than LEDs.

This schematic illustrates the novel nanosheet with three parallel segments created by the researchers, each supporting laser action in one of three elementary colors. The device is capable of lasing in any visible color, completely tunable from red, green to blue, or any color in between. When the total field is collected, a white color emerges.
Photo by: ASU/Nature Nanotechnology

ASU researchers created a novel nanosheet — a thin layer of semiconductor that measures roughly one-fifth of the thickness of human hair in size and roughly one-thousandth the thickness of human hair — with three parallel segments, each supporting laser action in one of three elementary colors. The device is capable of lasing in any visible color, completely tunable from red, green to blue or any color in between. When the total field is collected, a white color emerges.

Engineers in ASU’s Ira A. Fulton Schools of Engineering published their findings in the July 27 advance online publication of the journal Nature Nanotechnology. Cun-Zheng Ning, professor in the School of Electrical, Computer and Energy Engineering, wrote the paper, “A monolithic white laser,” with his doctoral students Fan Fan, Sunay Turkdogan, Zhicheng Liu and David Shelhammer.

The advance puts lasers a step closer to being a mainstream light source and potential replacement or alternative to light emitting diodes. Lasers are brighter, more energy efficient, and can potentially provide more accurate and vivid colors for displays like computer screens and televisions. Ning’s group has already shown that their structures could cover as much as 70 percent more colors than the current display industry standard.

Another important application could be in visible light communication in which the same room lighting systems could be used for illumination and communication. The technology under development is called Li-Fi for light-based wireless communication, as opposed to the more prevailing Wi-Fi using radio waves. Li-Fi could be more than 10 times faster than current Wi-Fi, and white laser Li-Fi could be 10 to 100 times faster than LED based Li-Fi under development.

“The concept of white lasers first seems counterintuitive because the light from a typical laser contains exactly one color, a specific wavelength of the electromagnetic spectrum, rather than a broad-range of different wavelengths,” Ning explained. “White light is typically viewed as a complete mixture of all of the wavelengths of the visible spectrum.”

Sandia National Labs in 2011 produced high-quality white light from four large lasers. The researchers showed that the human eye is as comfortable with white light generated by diode lasers as with that produced by LEDs, inspiring others to advance the technology.

But “those independent lasers cannot be used for room lighting or in displays,” Ning said. “A single tiny piece of semiconductor material emitting laser light in all colors or in white is desired.”

Semiconductors, usually a solid chemical element or compound arranged into crystals, are widely used for computer chips or for light generation in telecommunication systems. They are used to make lasers and LEDs because they can emit light of a specific color when a voltage is applied to them. The most preferred light emitting material for semiconductors is indium gallium nitride, though other materials such as cadmium sulfide and cadmium selenide also are used for emitting visible colors.

The main challenge lies in the way light emitting semiconductor materials are grown and how they emit light of different colors. Typically a semiconductor emits light of a single color — blue, green or red — that is determined by a unique atomic structure and energy bandgap.

The “lattice constant” represents the distance between the atoms. To produce all possible wavelengths in the visible spectral range you need several semiconductors of different lattice constants and energy bandgaps.

“Our goal is to achieve a single semiconductor piece capable of laser operation in the three fundamental lasing colors. The piece should be small enough so that people can perceive only one overall mixed color instead of three individual colors,” said Fan. — Sharon Keeler, chief media officer, Ira A. Fulton Schools of Engineering. Read more about the research here.

Laser Safety Community Focused on Safeguarding Consumers Who Are Attending Light Shows and Acquiring Pointers

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A December 2013 laser light show in France. Source: Wikipedia Commons/Kergourlay

By Geoff Giordano

With plenty of summer left to enjoy, it is appropriate to remind revelers to be aware when attending outdoor laser demonstrations or using handheld laser pointers. More and more handheld laser pointers are being sold to consumers and tourists — especially online — and they often exceed the output power listed on the label.

As lasers continue to break new ground as tools of healing, communication and entertainment, knowing how to avoid beam-related eye and skin injuries is paramount. New research illustrates the need for consumers to use caution and be aware of potential dangers.

A study presented at LIA’s International Laser Safety Conference in March warned of the dangers laser pointers present to youths. The study, led by U.K. ophthalmologist Fahd Quhill and related by ILSC General Chair John O’Hagan of Public Health England, presented cases of permanent eye damage suffered by five children in Sheffield, England. Consumer lasers given as gifts or acquired from websites, tourist destinations or modified commercial products cost some of those children more than 50 percent of their vision.

“What do you do” when a laser-related eye injury suffered by a youngster “wipes out the possibility of a whole range of career opportunities (for them)?” O’Hagan asked.

One move toward a solution came in February 2014 with a decision by the European Commission to put controls on laser products intended for consumers. According to O’Hagan, the decision indicates that “child-appealing products shall not cause damage to the eyes or skin in case of any exposure that could occur under any conditions of use, including deliberate, long-term exposure with optical viewing instruments.” The broadly applicable statement also helps regulate products intended for home hair removal. The decision allows the manufacture of products “that can do something to the skin providing (they) can’t harm the eye,” O’Hagan explained.

Meanwhile, increasingly popular laser light displays at concerts and festivals can pose a danger to spectators from unintended exposures to the laser source. Peter Blattner of the Swiss Federal Institute of Metrology (METAS) discussed the agency’s real-time assessment of laser shows and potential irradiation of spectators. The system was tested successfully in the field at about 20 laser shows in Switzerland, those tests often mandated by regulators or show operators. The tests found that all the shows exceeded maximum permissible exposure limits, Blattner said — some by up to 120 times those limits. The shows were adjusted to acceptable levels.

The challenge with laser light shows, said James Stewart of LVR Optical, is that “one minute they are quite smooth and fluid beams, the next minute they can (become) very stationary for a few milliseconds — enough time to create these accentuated, tight finger beams of light.”

Stewart and Blattner noted the prevalence of lower-cost laser projectors available to show organizers.

“As far as nightclubs go,” Stewart explained, “the entry-level (power) is three watts.” He notes that many people who attend his training sessions after recently purchasing a three-watt or five-watt laser for light shows “become a bit disillusioned” when they learn they can’t use the system to scan the crowd in their small venue.

In larger-scale uses, laser systems are typically eight to 30 watts, Stewart said, but typically only one to three watts would be used to scan an audience. He has been involved in assessing audience-scanning laser light shows presented by major global recording artists when they performed in the U.K. Even a one-watt laser will be hazardous at around 200 meters, he noted.

While show presenters can alter the laser beam to be less harmful to audiences, to avoid injury at shows, it is generally advisable not to intentionally stare or look at where the laser beam is coming from.

As O’Hagan pointed out, in some cases people struck in the eye by a beam from a handheld laser pointer were not injured by the beam but from rubbing their eyes after the fact.

To help inform the public, LIA created a primer on laser pointers and tips for using them safely. The guidelines are intended to be shared freely in the hopes of helping avoid accidents.

LIA advises the following in regard to laser pointers:

  • Never shine a laser pointer at anyone. Laser pointers are designed to illustrate inanimate objects.
  • Do not allow minors to use a pointer unsupervised. Laser pointers are not toys.
  • Do not point a laser pointer at mirror-like surfaces. A reflected beam can act like a direct beam on the eye.
  • Do not purchase a laser pointer if it does not have a caution or danger sticker on it identifying its class. Report suspicious devices to the FDA.

Geoff is LIA’s communications director. Contact him at ggiordano@lia.org to share your experiences with lasers, sound off on issues regarding any facet of laser technology, suggest stories or offer your commentary with a guest article or blog post.