Ken Jones, former Vitesse vice president and general manager of its Advanced Transmission Div., has been appointed president and CEO and a member of the board at Scotland-based Essient Photonics.    . . .   IRIDEX Corp. has begun revenue shipments of its EndoLase green laser photocoagulator module, which will be incorporated into the Bausch & Lomb Millennium microsurgical system, used by vitreo-retinal surgeons for operating room procedures.   . . .   R2 Technology Inc. announced it has made a product development and license agreement with Chroma Medical Systems Inc. to develop computer-aided detection technology for computed tomography-based virtual colonoscopy, also known as CT colonography.