Researchers have developed a new compact and ultra-fast powerful yellow laser. The tunable laser exhibits superior beam quality and helps meet the need for a practical yellow light source that emits ultra-fast light pulses, Optics Letters reports.
“The orange-yellow spectral range is highly absorbed by hemoglobin in the blood, making lasers at these wavelengths especially useful for biomedical applications, dermatological treatments and eye surgery,” explains Anirban Ghosh from the Photonic Science Laboratory at the Physical Research Laboratory in India and a member of the research team …
A femtosecond tunable yellow laser source can aid in medical procedures that cause less thermal damage and where more selective laser exposure is needed than is currently available.
The researchers, led by Gutam K. Samantha, describe how they used an optical phenomenon called nonlinear frequency conversion to convert mid-infrared laser light into yellow light that can be tuned from 570 to 596 nanometers.
“We are demonstrating reliable, powerful, ultra-fast, tunable yellow light in a fairly simple experimental configuration,” said Ghosh.
Although research has shown that laser light in the yellow spectral range is optimal for a variety of medical procedures, such wavelengths are usually generated using bulky and ineffective copper vapor lasers, dye lasers and parametric light generators.
Researchers have created a more practical laser using a newly developed ultra-fast solid-state mid-infrared laser and a two-step frequency doubling process. Doubling the frequency of an ultrafast laser is a tricky process that requires identifying the correct crystal to produce high-quality laser light with the desired properties.
Tests on the new laser have shown that it can deliver a maximum average output power of over 1 W with 130 femtosecond pulses at a repetition rate of 80 MHz with an outstanding spatial beam profile. The laser also showed excellent power stability over time.