Translation. Region: Russian Federal
Source: Novosibirsk State University – Novosibirsk State University –
Research staff Department of Laser Physics and Innovative Technologies, Novosibirsk State University (OLFIT NSU) optimized birefringent filters for use in fiber lasers. NSU scientists were far from the first specialists in the field of photonics who, with varying degrees of success, used these filters in fiber lasers, but they summarized and analyzed the previous experience of their colleagues and proposed their own innovative solution for their optimization. The results of this work are presented in the article by the head of the Department of Laser Physics and Innovative Technologies of NSU, Doctor of Physical and Mathematical Sciences Sergey Kobtsev “Bifractive Filters in Fiber Systems” (“Birefringent filters in fiber systems”), which was published in the international scientific journal “Journal of the Optical Society of America B” It became one of the most downloaded in January-March 2025.
— We have been working with birefringent filters for many years. Several works were devoted to improving filters of this type, in which we considered birefringent filters as the main selectors of liquid and solid-state tunable lasers. Filters of this type have proven themselves in our traditional lasers from the best side. Naturally, there was a desire to use them in fiber lasers. It turned out that when adapting birefringent filters to fiber lasers, essentially only the operating principle of these filters remains, and their configuration undergoes significant changes. The article “Birefringent filters in fiber systems” shows options for these changes, analyzes the capabilities and limitations of modified filters. The article, of course, is of interest to a wide range of researchers and developers in the field of photonics, — explained Doctor of Physical and Mathematical Sciences Sergey Kobtsev.
Interest in laser spectral-selective components from photonics specialists is quite high, since such elements allow in many cases to achieve the required laser line width and/or control the radiation wavelength. Birefringent filters, whose action is based on changing the polarization of radiation when passing through a birefringent optical material, have long established themselves as one of the best spectral-selective components for lasers with a relatively wide gain band.
Filters of this type are widely used in tunable dye lasers or titanium-sapphire lasers. They typically contain one or more birefringent plates (usually made of crystalline quartz) inclined at the Brewster angle to the beam.
The inclined surfaces of the plates act as partial radiation analyzers, and the plates themselves act as radiation polarizers. The wavelengths of radiation whose polarization does not change when passing through the filter are generated.
— Most fiber lasers are tunable, their radiation wavelength can be changed by tens of nanometers. This change can be made using birefringent filters, but they require adaptation to fiber lasers. As a result of attempts to use these filters in fiber lasers, there was a need for new solutions to adapt birefringent filters to a relatively new platform with original properties. The article “Birefringent filters in fiber systems” is devoted to the analysis of changes in these filters (material, configuration, controllability, etc.) associated with their use in new conditions. Optimized birefringent filters are in demand in many fiber lasers, widely used in various tasks – from medicine to cooling atoms. It would not be an exaggeration to say that thanks to the efforts of NSU scientists, one of the key elements of fiber lasers is being improved, — explained Sergey Kobtsev.
The research described in the article is carried out within the framework of the project “New fiber short-pulse laser systems including advanced composite materials, intelligent technologies and metrological extensions”, supported by the Ministry of Science and Higher Education of the Russian Federation.
Please note: This information is raw content directly from the source of the information. It is exactly what the source states and does not reflect the position of MIL-OSI or its clients.