Dr. Lewis Carpenter of Excelitas Technology

Fabry-Perot optical resonators have transverse and longitudinal spatial modes with narrow spectral resonances. Such resonances have been used for spectral selection in tunable Fabry-Perot filters. Multiple transverse modes cause unwanted signal distortion in such spectral selection. In analogy with single mode optical fibers, we have discovered and developed such filters with fundamentally single transverse mode operation for use in optical spectral analyzers.

In another aspect, Fabry-Perot filters select a narrow spectral slice in transmission, while reflecting a broadband rejected signal. For tunable external cavity semiconductor laser operation, reflective spectral filter is required for sending a narrow selected tunable spectral slice as feedback to the semiconductor gain chip. We have discovered a new reflective operating regime of Fabry-Perot filters, where a narrow spectral slice is reflected by the filter.

I will describe the theory of these novel Fabry-Perot filters, their implementation in tunable silicon Micro-Electro-Mechanical-System MEMS format, and commercial applications to spectral analyzers for fiber optical telecom signals and fast tunable semiconductor lasers for Swept-Source Optical Coherence Tomography SS-OCT in medical tissue imaging.

Biography:

Mark Kuznetsov received ScD degree from MIT, group of Erich Ippen and Hermann Haus, in the field of short pulse generation in semiconductor lasers. He then worked at AT&T Bell Laboratories, Crawford Hill, on tunable semiconductor lasers and other devices for wavelength-division-multiplexed WDM optical networks. Working at a small startup Micracor, with Aram Mooradian, he developed optically pumped semiconductor laser technology, OPSL, also known as VECSELs, vertical-external cavity surface-emitting lasers, which generate light in wavelengths by design from UV to IR with multi-watt class powers and high-quality beams, and are now widely deployed commercially, displacing legacy gas and solid-state lasers. At Raytheon, he has worked on passively Q-switched Nd:YAG microchip lasers. At MIT Lincoln Laboratory, he has worked on transmission aspects in WDM fiber optic telecom networks. For the past 25 years, he has worked at Axsun / Excelitas Technologies, developing Si micro-electro-mechanical system MEMS wavelength tunable technology, including Fabry-Perot tunable filters for channel monitoring in WDM optical networks and MEMS tunable semiconductor lasers, external cavity and VCSELs, for applications in spectroscopy and optical coherence tomography OCT in medical ophthalmic and cardiovascular imaging.