This video shows the construction and operation of a holographic optical tweezers.
Giuseppe Pesce, Giorgio Volpe, Onofrio M. Maragó, Philip H. Jones, Sylvain Gigan, Antonio Sasso, and Giovanni Volpe, “Step-by-step guide to the realization of advanced optical tweezers,” J. Opt. Soc. Am. B 32, B84-B98 (2015).
http://dx.doi.org/10.1364/JOSAB.32.000B84