“…Experimentally, five diffracted laser beams generated by using phase masks [18,19], flat-top prisms [20,21], two beam interference, four beam interference, special prism and combined holographic gratings as beam splitter (BS) have been involved in the fabrication of PCs by interference holographic lithography [22]. However, by using two beam multiexposure interference technique [23,24] has many advantages over the commonly used multi-beam interference technique; such as experimental simplicity, easy fabrication of different structures with long range and high contrast of structures [25] are few examples.…”