光貿易株式会社
〒113-0034
東京都文京区湯島3-13-8
湯島不二ビル301
電話番号：03-3832-3117
FAX番号 ：03-3832-3118
Optoplex Corporation社
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■メーカーの紹介 |
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| ■製品概要／Product Overview | |
Six-port hybrid devices have been used for microwave and millimeter-wave detection systems since the mid-1990s and are a key component for coherent receivers. In principle, the six-port device consists of linear dividers and combiners interconnected in such a way that four different vectorial additions of a reference signal (LO) and the signal to be detected are obtained. The levels of the four output signals are detected by balanced receivers. By applying suitable baseband signal processing algorithms, the amplitude and phase of the unknown signal can be determined. For optical coherent detection, the six-port 90°optical hybrid would mix the incoming signal with the four quadratural states associated with the reference signal in the complex-field space. The optical hybrid would then deliver the four light signals to two pairs of balanced detectors. See below block diagram for 90° optical hybrid and a coherent receiver.  Optoplex's passive free-space micro-optics-based 90o optical hybrid is suitable for coherent signal demodulation for either homodyne or heterodyne detection. The patent-pending, broadband device accepts the two optical signals (S & L) and generates four output signals: S+L, S-L, S+jL, S-jL, as shown below. When these signals are detected by two balanced receivers, both the amplitude and the relative phase information between the input signals can be extracted via differential detection and digital signal processing. Moreover, in a coherent system, the preservation of the optical phase can be used to cost-effectively compensate optical transmission impairments in the electrical domain.  |
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| ■特徴／Key Features |
| - Purely passive device (no need for external electric power) - Compact size - Based on free-space bulk-optics design - DPSK modulation is a prerequisite for adapting coherent detection |
| ■アプリケーション／Application |
| - For coherent signal demodulation and detection - For the next-generation optical transmission system - Key component for the optical coherent detection (a detection format which has been widely used in many other communication methods, such as radio and wireless) |