A laser noise reduction method for holographic pickup heads

There are several methods to avoid optical feedback and reduce laser noise in optical recording systems. However, most of them utilize high cost optical components or electronics or increase the pickup head size. Furthermore, it is difficult to fit these components into in a small package like a holographic laser module. In this paper, a simple method for avoiding feedback noise in a holographic pickup head is proposed. A single wave plate is added to the optical system to rotate the polarization of the laser feedback to be orthogonal to the emitting polarization state. Experimental results show that it is feasible and practically reduces laser noise