1. Diana Chin 1, Peter Taylor 1,2, YenTing Chiu 1, and Claire Gmachl 1 1 Princeton University, Princeton, NJ 08544, USA 2 Permanent Address: DeSales University, Center Valley, PA 18034, USA

2. Background/ Motivation A more refined laser beam is necessary for the QC laser to be effective in gas detection applications. Part I: Imaging the far-field pattern of the original laser beam Part II: Coupling the light into fibers and comparing the resulting intensity profiles

3. Imaging the Far-field Pattern MCT detector vs FLIR (Forward Looking InfraRed) Camera Intensity Angle (degrees)

4. Mode Filtering with Fibers Thank you to the Harrington group at Rutgers University for the fibers!

5. Results

6. Conclusion Based on the close resemblance of the resulting far-field pattern to a Gaussian profile, the single mode fiber was successful in refining the QC laser beam by filtering out the majority of its higher order modes. Further experiments are necessary to determine if better alignment and coupling of the laser will yield an intensity distribution even closer to a true Gaussian. Holds great potential for future environmental applications, particularly in the detection of atmospheric gases.

7. Thank You!