Dichroic beam splitters having non-parallel entry and exit surfaces, reduced distance between such surfaces, and an aspherical exit surface can be advantageously used in dual channel optical systems, particularly when one channel is dedicated to infrared light and the other channel is dedicated to visible or near-infrared light. The drop-before-add optical routing and switching system includes an input waveguide for carrying a multiplexed optical signal comprising optical signals transmitted over a plurality of wavelength channels represented by \u03bb1, \u03bb2, \u03bb3,. The clamper receives an image signal and resets the DC voltage level of the image signal to generate a clamped signal. Some of the logic elements within the core include registers that are used as data registers for the multiple data rate interface. If the guest access request is associated with the member client, then the guest client is allowed to access the virtual reality environment via a guest avatar. For example, where human activity can be detected within the page or where the extraneous markup artifact becomes activated despite the extraneous nature of the artifact, a human requestor can be concluded.