Company Filing History:
5 out of 176 
3 out of 3 
2 out of 1,258 
Years Active: 1977-2002
Title: Innovations of I-Cheng Chang
Introduction
I-Cheng Chang is a prominent inventor based in Sunnyvale, CA, with a remarkable portfolio of 15 patents. His work primarily focuses on advanced acousto-optic tunable filters, which have significant applications in wavelength division multiplexing.
Latest Patents
One of his latest innovations is the phase array acousto-optic tunable filter based on birefringent diffraction. This acousto-optic tunable filter (AOTF) utilizes phased array transducers, allowing for dynamically reconfigurable wavelength division multiplexing. This new type of AOTF uniquely enables simultaneous and independent selection of multi-wavelength signals, separating them into multiple output ports. The preferred embodiments of this AOTF enhance resolution, narrow channel spacing, lower drive power, and reduce coherent crosswalk. Another significant invention is the polarization-independent acousto-optic tunable filter (PIAOTF). This filter is designed for multiwavelength switching and routing in wavelength division multiplexing (WDM) networks. The PIAOTF divides an incident unpolarized light beam to propagate and diffract along two polarization division branches. By employing polarization converters and equal optical paths for both channels, the PIAOTF minimizes polarization-dependent loss and polarization mode dispersion. Additionally, a preferred embodiment of the AOTF using an elongated acousto-optic interaction medium offers narrow bandwidth, lower drive power, and easier alignment.
Career Highlights
I-Cheng Chang has worked with notable companies, including I-Tek, Inc. His contributions to the field of acousto-optic technology have established him as a leading figure in this area of research and development.
Collaborations
Throughout his career, I-Cheng has collaborated with esteemed colleagues such as Farhang Sabet-Peyman and David L. Hecht. Their joint efforts have further advanced the innovations in acousto-optic technologies.
Conclusion
I-Cheng Chang's contributions to the field of acousto-optic tunable filters demonstrate his innovative spirit and technical expertise. His patents reflect a commitment to enhancing technology in wavelength division multiplexing, making significant strides in the industry.