Issued Patents 1989
Showing 1–4 of 4 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 4874216 | Variable-waveguide optical branching filter | Katsuyuki Utaka, Yuichi Matsushima, Shigeyuki Akiba | 1989-10-17 |
| 4852108 | Wavelength tunable semiconductor laser with narrow band-pass active filter region | Katsuyuki Utaka, Yuichi Matsushima | 1989-07-25 |
| 4805975 | Optical waveguide switch | Katsuyuki Utaka, Yuichi Matsushima | 1989-02-21 |
| 4795225 | Semiconductor optical switch | Yuichi Matsushima, Katsuyuki Utaka | 1989-01-03 |