Although gas lasers have been developed since the 1960s, there was a lull in in the pace of new concepts that began at the turn of the century as solid state lasers such as fiber and thin disk based systems came into vogue. However, the last decade has seen an uptick in new concepts, such as gas filled hollow core fiber lasers and optically pumped metastable noble gas lasers. A common driving force behind many of these new variants is the fruition of diode lasers at novel wavelengths and increasing powers. Research under this topic will focus on understanding the underlying physics of these new lasers.

A wide variety of experiments will be pursued to assess the potential for scaling new laser concepts. Researchers will have the opportunity to develop demonstrator lasers for feasibility studies as well as conduct more fundamental research including energy transfer mechanisms and measuring pressure broadening and shift rates. A variety of spectroscopic techniques, including tunable diode laser absorption spectroscopy and laser induced fluorescence, are currently being used but building and using new diagnostic tools such as Raman spectroscopy is also of interest. Experimental research is complimented by strong ongoing modeling and simulation efforts in the group. It is highly encouraged that researchers include an M&S focus within their research.

Specific topics of interest are: (1) understanding the energy transfer dynamics of gas filled hollow core fiber lasers, which includes measuring rotational and vibrational energy transfer rates, as well as collisional deactivation rates of the molecules of the fiber walls; (2) understanding time dependent temperature dynamic of these systems.

As laser systems mature and are being looked at for outdoor applications such as laser communications, there needs to be a systematic evaluation of their expected propgation characteristics.  There is a wealth of aerosol characterization data avaialble for most regions thourghout the world.  However diagnotics designed to understand absorption and scattering propoerties are centered in the UV-VIS wavelengths.    We are interested in 1) collecting data on absorption, scattering, extinction of aerosols at wavelengths a 1um-5um in different regions of the US including AK. 2) characterizing the chemical composition of aersols at different regions and 3) developing diagnostics that can quickly and accuratelt predict atmospheric propagation at a variety of wavlengths fomr 1-5um. 

 

References

Dadashzadeh N, Thirugnanasambandam M, Weerasinghe K, Debord B, Chafer M, Gérôme F, Benabid F, Washburn B, Corwin KL: "Near-Gaussian Spatial Mode from a Mid-IR Acetylene-filled Hollow-Core Fiber Laser". Frontiers in Optics 2016. OSA Technical Digest (online) (Optical Society of America, 2016), paper FTu1I.5

Wellegehausen B, Luhs W: “Diode-pumped CW molecular lasers”. Applied Physics B 122: 133, 2016

 

key words

Hollow core fiber; Gas laser; Spectroscopy; Kinetics; Atmospheric Characterization

Citizenship:  Open to U.S. citizens

Level:  Open to Postdoctoral and Senior applicants