Shares of companies in the optical component sector, including Finisar (FNSR) and Oclaro (OCLR), are following Ciena (CIEN) lower on Thursday. Ciena offered up a gloomy view of the fourth quarter earlier today, despite reporting better than expected fiscal third-quarter earnings and revenue. The declines are especially notable as the broader tech sector is rallying hard going into the holiday weekend. Ciena, a global supplier of telecommunications networking equipment, operates in four segments: Converged Packet Optical, Packet Networking, Optical Transport, and Software & Services.