A well-defined photoresponsive polymethacrylate containing azo chromophores, poly[6-(4-phenylazophenoxy)hexylmethacrylate] [Poly(PPHM)], was prepared with azo-based monofunctional and difunctional initiators via atom transfer radical polymerization in the presence of CuCl/1,1,4,7,10,10-hexamethyltriethylenetetramine. The polymerizations with first-order kinetics were well controlled with theoretical expected molecular weight and narrow molecular weight distributions in two initiation systems. The UV absorption intensities of the poly (PPHM)s increased with increasing molecular weight of the poly(PPHM)s in all cases. The 80-nm surface-retief gratings with 2.7%, efficient diffraction formed on the poly (PPHM) film surface were obtained with a linearly polarized krypton laser with 10 min of irradiation at a recording beam intensity of 188 mW/cm(2) with a wavelength of 413.1 nm. (C) 2007 Wiley Periodicals, Inc.