A pit-edge detection method for tracking-error signals using a monolithic confocal laser coupler

We propose a novel tracking-error signal detection method based on the pit- edge detection method, using a monolithic confocal laser coupler with a con focal knife edge structure (CKE device). The new detection method, which we call the CKE pit-edge method, is applied to an optical disk system in whic h the optical disk has a pit depth of lambda/4n. In this paper, we compare this new method to the conventional pit-edge detection method using numeric al analysis and a Simple model. Further, we also show that both the CKE pit -edge method and our previously reported CKE push-pull method can utilize t he same CKE device.