Micro encoder with vertical cavity surface-emitting laser using enlarged diffractive image

Summary form only given. A newly developed micro encoder using vertical cavity surface-emitting laser (VCSEL) is presented in this paper. The VCSEL encoder has high resolution and easy handling, though the encoder head size is smallest in its resolution class. It can detect the moving amount, direction and the reference position of the scale with high resolution. These features are realized simultaneously by adopting VCSEL and multi-functional IC and by incorporating the Talbot diffraction technique). The encoder head consists of two VCSELs horizontally mounted onto a multi-functional photonic IC which has photodiode(PD) arrays, a laser driver circuit and a signal processing unit.