| Autor: |
Tae Kwan Oh, Eung Gi Paek, Joon Y. Choe |
| Rok vydání: |
1998 |
| Předmět: |
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| Zdroj: |
Technical Digest. Summaries of Papers Presented at the Conference on Lasers and Electro-Optics. Conference Edition. 1998 Technical Digest Series, Vol.6 (IEEE Cat. No.98CH36178). |
| DOI: |
10.1109/cleo.1998.676382 |
| Popis: |
Recent interest in WDM increasingly demands a faster tunable spectral filter with a narrower bandwidth with weak sidelobes to permit a larger number of wavelength channels within the erbium-doped fiber amplifier (EDFA) passband. However, most current acousto-optic tunable filters (AOTFs) have broad spectral bandwidths due to the limited-time-bandwidth product or a refractive-index change of an acousto-optic device at 1.55 /spl mu/m. The spectral bandwidth of an AOTF can be significantly reduced by inserting a diffraction grating in the light path just after the acousto-optic beam deflector (AOBD). Instead, the tuning range is reduced by the same ratio, because the time-bandwidth product is fixed. By optimizing an AOBD with a large bandwidth and a slow acoustic velocity combined with a diffraction grating with a suitable grating period, a narrow bandwidth of 0.2 nm and a broad tuning range of 50 nm-enough to cover the entire EDFA passband-are experimentally obtained. The result implies a significantly increased number of available wavelength channels. The improvement is by a factor of /spl sim/20. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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