An adaptive wavelength tunable optical filter employing an angle-tuned interference filter and an intelligent digital controller

Abstract

This paper describes an adaptive wavelength tunable optical filter, which is composed of an angle-tuned interference optical filter and an intelligent digital controller. The new angle-tuned interference filter consists of a dielectric interference optical filter and a piezoelectric angle-tuning mechanism. It achieves quick wavelength switching within 2.5 ms in a 30 nm tuning range and a sufficiently low crosstalk less than -30 dB. The intelligent digital controller has two functions: wavelength tracking and wavelength channel selection. Combining these technologies, we have developed a practical low-cost tunable filter suitable for a post-optical-amplifier filter in a high-sensitivity detection system and a channel selector in a WDM system that requires 10-100 ms channel selection time. With a wavelength tracking operation, we have confirmed -35 dBm high-sensitivity detection in 20 nm wavelength range in a 10 Gb/s system. We have also confirmed a wavelength channel selection operation within 18 ms in a three-channel wavelength division multiplexed (WDM) system whose channel spacing is 4.4 nm.

Development of a 3D HUD using a tunable bandpass filter for wavelength multiplexing

“…Paper presents such a system, using a piezoelectric actuator to tune the wavelength frequency. Whereas the dynamic characteristics of this system suit our application, the filter size needed for our HUD optical engine is too large for this kind of actuator.…”

A thin film filter (TFF) based three-port tunable optical filter

“…By optimizing the stack structure, a 100GHz angle-tuned filter with low polarization dependent loss has been designed. Nowadays, people pay more attention to the tunable filters base on angletuned thin film filter due to its simple structure and low cost [5]- [7]. In this paper a new structure of three-port tunable filter base on the angle-tuned filter is also proposed.…”

Design of non-polarization angle-tuned narrowband thin film filter

“…With the low insertion loss, high adjacent channel isolation and good temperature stability, the multiple-cavities narrowband dielectric thin film filter is widely used in the DWDM system [1]. As the incident angle is increasing, its transmission peak will shift to shorter wavelength, which can be used to fabricate the angle-tuned filter to select the specific wavelength from the multiple wavelengths [2][3][4]. However, the bandwidths and the central wavelengths of the S-polarization and P-polarization light will separate obviously when the multiple-cavities narrowband dielectric thin film filter is in oblique incidence.…”