Improvements in Laser Technology
In a paper appearing in the journal Science, Caltechs Alireza Marandi, an assistant teacher of electrical engineering and applied physics, describes a brand-new approach developed by his lab for making this type of laser, referred to as a mode-locked laser, on a photonic chip. The lasers are made utilizing nanoscale parts (a nanometer is one-billionth of a meter), enabling them to be integrated into light-based circuits comparable to the electricity-based integrated circuits found in modern electronic devices.
A nanophotonic mode-locked laser built on lithium niobate gives off a beam of green laser light. Credit: Caltech
” Were not just interested in making mode-locked lasers more compact,” Marandi says. “We are thrilled about making a well-performing mode-locked laser on a nanophotonic chip and combining it with other elements. Thats when we can develop a total ultrafast photonic system in an integrated circuit. This will bring the wealth of ultrafast science and technology, currently coming from meter-scale experiments, to millimeter-scale chips.”
Ultrafast Lasers and Nobel Prize Recognition
Ultrafast lasers of this sort are so essential to research study, that this years Nobel Prize in Physics was awarded to a trio of scientists for the development of lasers that produce attosecond pulses (one attosecond is one-quintillionth of a 2nd). Such lasers, however, are currently incredibly costly and bulky, says Marandi– who notes that his research is checking out techniques to accomplish such timescales on chips that can be orders of magnitude more affordable and smaller, with the objective of developing inexpensive and deployable ultrafast photonic technologies.
” These attosecond experiments are done nearly specifically with ultrafast mode-locked lasers,” he states. “And some of them can cost as much as $10 million, with an excellent chunk of that expense being the mode-locked laser. We are really thrilled to consider how we can replicate those experiments and performances in nanophotonics.”
Ingenious Nanophotonic Mode-Locked Laser
At the heart of the nanophotonic mode-locked laser established by Marandis laboratory is lithium niobate, a synthetic salt with special optical and electrical residential or commercial properties that, in this case, allows the laser pulses to be controlled and formed through the application of an external radio-frequency electrical signal. This approach is referred to as active mode-locking with intracavity phase modulation.
” About 50 years back, scientists used intracavity phase modulation in tabletop experiments to make mode-locked lasers and chose that it was not a fantastic fit compared to other strategies,” says Qiushi Guo, the very first author of the paper and a previous postdoctoral scholar in Marandis laboratory. “But we discovered it to be an excellent suitable for our incorporated platform.”
” Beyond its compact size, our laser also exhibits a series of appealing properties. For example, we can specifically tune the repeating frequency of the output pulses in a vast array. We can utilize this to develop chip-scale stabilized frequency comb sources, which are important for frequency metrology and accuracy picking up,” adds Guo, who is now an assistant professor at the City University of New York Advanced Science Research.
Future Goals and Research Impact
Marandi states he intends to continue improving this innovation so it can run at even much shorter timescales and greater peak powers, with a goal of 50 femtoseconds (a femtosecond is one-quadrillionth of a 2nd), which would be a 100-fold enhancement over his current gadget, which creates pulses 4.8 picoseconds in length.
The paper describing the research is titled “Ultrafast mode-locked laser in nanophotonic lithium niobite” and appears in the November 9 concern of Science.
Recommendation: “Ultrafast mode-locked laser in nanophotonic lithium niobate” by Qiushi Guo, Benjamin K. Gutierrez, Ryoto Sekine, Robert M. Gray, James A. Williams, Luis Ledezma, Luis Costa, Arkadev Roy, Selina Zhou, Mingchen Liu and Alireza Marandi, 9 November 2023, Science.DOI: 10.1126/ science.adj5438.
Co-authors are Benjamin K. Gutierrez (MS 23), graduate student in used physics; electrical engineering graduate trainees Ryoto Sekine (MS 22), Robert M. Gray (MS 22), James A. Williams, Selina Zhou (BS 22), and Mingchen Liu; Luis Ledezma (PhD 23), an external affiliate in electrical engineering; Luis Costa, formerly at Caltech and now with JPL, which Caltech handles for NASA; and Arkadev Roy (MS 23, PhD 23), previously of Caltech and now with UC Berkeley.
Funding for the research study was supplied by the Army Research Office, the National Science Foundation, and the Air Force Office of Scientific Research.
Scientists have developed a new method to produce compact mode-locked lasers on photonic chips, using lithium niobate for active mode-locking. This innovation guarantees to bring large-scale ultrafast laser experiments to a chip-scale format, with plans to more shorten pulse periods and increase peak powers.
Caltech has innovated an approach for developing compact, integrated mode-locked lasers on photonic chips, possibly changing ultrafast laser applications to smaller sized scales with boosted performance.
Lasers have become fairly commonplace in everyday life, but they have numerous usages outside of providing light programs at raves and scanning barcodes on groceries. Lasers are also of terrific value in telecommunications and computing along with physics, chemistry, and biology research study.
The Value of Ultrashort Laser Pulses
In those latter applications, lasers that can release incredibly short pulses– those on the order of one-trillionth of a 2nd (one picosecond) or much shorter– are specifically useful. Using lasers running on such small timescales, scientists can study physical and chemical phenomena that happen incredibly rapidly– for instance, the making or breaking of molecular bonds in a chain reaction or the movement of electrons within materials. These ultrashort pulses are likewise thoroughly utilized for imaging applications because they can have very big peak intensities however low typical power, so they avoid heating or perhaps burning up samples such as biological tissues.
In those latter applications, lasers that can produce incredibly short pulses– those on the order of one-trillionth of a 2nd (one picosecond) or much shorter– are especially useful.” Were not simply interested in making mode-locked lasers more compact,” Marandi states. “We are excited about making a well-performing mode-locked laser on a nanophotonic chip and integrating it with other elements.” These attosecond experiments are done practically solely with ultrafast mode-locked lasers,” he states. “And some of them can cost as much as $10 million, with an excellent chunk of that expense being the mode-locked laser.
