Sidelobe suppression in an acousto‐optic filter with a raised‐cosine interaction strength
Sidelobe suppression in an acousto‐optic filter with a raised‐cosine interaction strength
复制标题
具有升余弦相互作用强度的声光滤波器中的旁瓣抑制
DOI：
10.1063/1.107704
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发表时间：
1992
影响因子：
4
通讯作者：
J. Johnson
中科院分区：
文献类型：
--
作者：
D. Smith;J. Johnson
我们已经证明了中心通带为1530 nm的变迹相互作用强度导波声光滤光器的强度旁瓣降低了10分贝。声强度加权是通过在直声波导中发射声表面波(SAW)波束，并将该声表面波强度逐渐传输到有源器件，然后通过在19 mm的相互作用长度上通过20μm势垒的逝去波耦合来实现的。对于突然开始和截断相互作用的非变迹滤波器，其旁瓣强度为−5分贝，而对于升余弦加权的声表面波强度，旁瓣最多降至−15分贝。对于2.0 nm宽的变迹滤光片，在输入功率为80 mW时，转换效率达到97%。
We have demonstrated a 10‐dB reduction in the intensity sidelobes of an apodized‐interaction‐strength guided‐wave acousto‐optic filter with a center passband of 1530 nm. Acoustic‐intensity weighting was achieved by launching a surface acoustic wave (SAW) beam in a straight acoustic waveguide, and gradually transferring this SAW intensity to the active device, and back out, by evanescent‐wave coupling across a 20 μm barrier over a 19‐mm interaction length. The intensity sidelobe was −5 dB for an unapodized filter with abrupt onset and cutoff of the interaction, but sidelobes were reduced to at most −15 dB for a SAW intensity with raised‐cosine weighting. A conversion efficiency of 97% was achieved with 80 mW input power for the 2.0‐nm‐wide apodized filter.