Beam shaping and high-speed, cylinder-lens-free beam guiding using acousto-optical deflectors without additional compensation optics.

Using acousto-optical deflectors at high deflection speeds via acoustical frequency chirping induces astigmatism, deforming the laser beam in an unfavorable way. Within the paper, we present a method to prevent this effect for an ultrashort pulsed laser beam via acoustical frequency jumps synchronized to the pulse-to-pulse pause. We also demonstrate and give a method to calculate beam shaping capability of acousto-optical deflectors via arbitrary spatial frequency developments during ultrashort laser pulse transit through the deflector. Cylinder-lens-free deflection at >2000 rad/s and beam shaping capability is demonstrated experimentally. In our experiments the switching time between two beam shapes is 1 µs.

[1]  K Nemoto,et al.  Transformation of a laser beam intensity profile by a deformable mirror. , 1996, Optics letters.

[2]  A. Laskin,et al.  πShaper – Refractive Beam Shaping Optics for Advanced Laser Technologies , 2011 .

[3]  T. Sejnowski,et al.  A Compact Multiphoton 3D Imaging System for Recording Fast Neuronal Activity , 2007, PloS one.

[4]  Euan McLeod,et al.  High-speed varifocal imaging with a tunable acoustic gradient index of refraction lens. , 2008, Optics letters.

[5]  E. Mcleod,et al.  Dynamic pulsed-beam shaping using a TAG lens in the near UV , 2008 .

[6]  Craig B. Arnold,et al.  Enhanced depth of field laser processing using an ultra-high-speed axial scanner , 2013 .

[7]  Eric Audouard,et al.  Programmable focal spot shaping of amplified femtosecond laser pulses. , 2005, Optics letters.

[8]  N Friedman,et al.  Acousto-optic scanning system with very fast nonlinear scans. , 2000, Optics letters.

[9]  I. Chang I. Acoustooptic Devices and Applications , 1976, IEEE Transactions on Sonics and Ultrasonics.

[10]  Guido Hennig,et al.  Ultrafast Scan Techniques for 3D-μm Structuring of Metal Surfaces with high repetitive ps-laser pulses , 2011 .

[11]  Véronique Quintard,et al.  Acousto‐optic deflector‐based optical packet synchronization , 2000 .

[12]  N. Davidson,et al.  Acousto-optic lens with very fast focus scanning. , 2001, Optics letters.

[13]  P. Saggau,et al.  Random-access Multiphoton (ramp) Microscopy Fast Functional Imaging of Single Neurons Using , 2005 .

[14]  Keming Du Thin layer ablation with lasers of different beam profiles: energy efficiency and over filling factor , 2009, LASE.

[15]  Keith J. Kelleher,et al.  Three-dimensional random access multiphoton microscopy for functional imaging of neuronal activity , 2008, Nature Neuroscience.

[16]  R. Silver,et al.  A compact Acousto-Optic Lens for 2D and 3D femtosecond based 2-photon microscopy. , 2010, Optics express.