1. Thorlabs Crystalline Solutions 1 , Santa Barbara, California 93101, USA
2. Department of Physics, Syracuse University 2 , Syracuse, New York 13244, USA
3. LIGO Laboratory, California Institute of Technology 3 , Pasadena, California 91125, USA
4. Stanford University 4 , Palo Alto, California 94309, USA
5. LIGO Laboratory, Massachusetts Institute of Technology 5 , Cambridge, Massachusetts 02142 USA
6. Department of Physics, Embry-Riddle Aeronautical University 6 , Prescott, Arizona 86301, USA
7. Department of Physics, American University 7 , Washington, DC 20016, USA
8. JILA, National Institute of Standards and Technology and University of Colorado 8 , Boulder, Colorado 80309, USA
9. Physikalisch-Technische Bundesanstalt 9 , 38116 Braunschweig, Germany
10. Department of Physics, Hobart and William Smith Colleges 10 , Geneva, New York 14456, USA
11. Maastricht University 11 , 6200 MD Maastricht, The Netherlands
12. Nikhef 12 , 1098 XG Amsterdam, The Netherlands