Figure 2

Spatial variation of aberrations in specimens. (a) THG microscope images show cross-sections of waveguide structures laser written at different depths in fused silica. The yellow arrow shows the two depths for which aberration correction was optimized. The signal falls significantly away from the corrected depth. (b, c) Spatial maps show the variation of two mirror deformation aberration modes (b) coma and (c) spherical across a cross-section of a Caenorhabditis elegans specimen (the mirror deformation mode amplitudes are approximately equivalent to r.m.s. phase in radians at λ=1.2 μm). r.m.s., root mean square; THG, third harmonic generation.