Tham khảo tài liệu 'athermal design and analysis for wdm applications', kỹ thuật - công nghệ, kĩ thuật viễn thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Header for SPIE use Athermal design and analysis for WDM applications Keith B. Doyle Optical Research Associates Westborough MA Jeffrey M. Hoffman Optical Research Associates Tucson AZ ABSTRACT Telecommunication wavelength division multiplexing systems WDM demand high fiber-to-fiber coupling to minimize signal loss and maximize performance. WDM systems with increasing data rates and narrow channel spacing must maintain performance over the designated wavelength band and across a wide temperature range. Traditional athermal optical design techniques are coupled with detailed thermo-elastic analyses to develop an athermal optical system under thermal soak conditions for a WDM demultiplexer. The demultiplexer uses a pair of doublets and a reflective Littrowmounted grating employed in a double-pass configuration to separate nine channels of data from one input fiber into nine output fibers operating over the C-band 1530 to nm . The optical system is achromatized and athermalized over a 0 C to 70 C temperature range. Detailed thermo-elastic analyses are performed via a MSC NASTRAN finite element model. Finite element derived rigid-body positional errors and optical surface deformations are included in the athermalization process. The effects of thermal gradients on system performance are also evaluated. A sensitivity analysis based on fiber coupling efficiency is performed for radial axial and lateral temperature gradients. Keywords wavelength division multiplexing athermal optical design fiber coupling efficiency thermo-elastic analysis integrated modeling thermal gradients 1. INTRODUCTION In the field of telecommunications wavelength-division multiplexing is used in fiber-optic systems to transmit signals at different wavelengths through a single fiber to increase transmission capacity without having to install new fiber. Demultiplexers are used to separate the individual wavelengths from a fiber carrying multiple channels wavelengths as shown in Fig. 1. A wide
