Methods and apparatus are presented for obtaining high-resolution 3-D images of a sample over a range of wavelengths, optionally with polarisation-sensitive detection. In preferred embodiments a spectral domain OCT apparatus is used to sample the complex field of light reflected or scattered from a sample, providing full range imaging. In certain embodiments structured illumination is utilised to provide enhanced lateral resolution. In certain embodiments the resolution or depth of field of images is enhanced by digital refocusing or digital correction of aberrations in the sample. Individual sample volumes are imaged using single shot techniques, and larger volumes can be imaged by stitching together images of adjacent volumes. In preferred embodiments a 2-D lenslet array is used to sample the reflected or scattered light in the Fourier plane or the image plane, with the lenslet array suitably angled with respect to the dispersive axis of a wavelength dispersive element such that the resulting beamlets are dispersed onto unique sets of pixels of a 2-D sensor array.