Randy A Bartels

US Patent:

7576907, Aug 18, 2009

Filed:

May 12, 2008

Appl. No.:

12/119443

Inventors:

Randy A. Bartels - Fort Collins CO, US
Jesse W. Wilson - Fort Collins CO, US
Philip Schlup - Fort Collins CO, US

Assignee:

Colorado State University Research Foundation - Fort Collins CO

International Classification:

G02B 1/29

US Classification:

359298, 359300, 359302, 359279

Abstract:

Simultaneous amplitude and phase control of ultrafast laser pulses using a single, linear (one-dimensional) liquid crystal spatial light modulator is described. Amplitude shaping is accomplished by writing a high-frequency phase grating having a spatial period much smaller than the spectral focus (over-sampling), onto the modulator, and diffracting away selected frequencies in a controllable manner, while spectral phase control is imparted by adding an appropriate slow phase bias to the modulator. The close pixel spacing, large number of pixels, and small footprint of the reflective spatial light modulator employed with an angular wavelength dispersive element in a folded Martinez stretcher, enables a simple and compact apparatus to be achieved. The high reflectivity of the spatial light modulator results in a highly efficient pulse shaper when either a prism or diffractive grating is used for the angular dispersive element. The use of a transmissive spatial light modulator in an unfolded Martinez stretcher configuration is also described.