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Optical amplifier.
申请公布号：EP0469681(A1)
申请号：EP19910201963
申请日期：1991.07.29
申请公布日期：1992.02.05
发明人：THIJS, PETRUS JOHANNES ADRIANUS;TIEMEIJER, LUKAS FREDERIK
分类号：G02F1/35;H01S5/00;H01S5/0625;H01S5/10;H01S5/227;H01S5/34;H01S5/50
主分类号：G02F1/35
摘要：<p>The invention relates to an optical amplifier with a semiconductor body comprising a layer structure grown on a substrate (1), with an active layer (4) between two cladding layers (2,5), a strip-shaped amplification region being bounded by two end faces (7,8) of low reflection which form the input and output faces for the radiation to be amplified. The active layer (4) comprises a number of quantum well (QW) layers with direct band transition, and separated by barrier layers of a different semiconductor material, a first portion of which QW layers is under tensile stress. Such amplifiers are used inter alia in optical glass fibre communication systems. The known amplifier is owing to the tensile stress, less sensitive to polarization but the amplification can not be obtained at a minimal current. According to the invention, another portion of the layers forming part of the active layer is under compressive stress. Owing to the compressive stress present locally in the amplification region, the TE-mode is more strongly amplified there than the TM-mode, while in the tensile portion of the amplification region the TM-mode is more strongly amplified than the TE-mode. This enables realisation of a polarization insensitive amplifier with higher stress and thus with a large amplification at a relatively low current. In one embodiment, both portions of QW layers are within one stack of layers containing the amplification region. In another embodiment both portions are positioned in different stacks that are located next to each other each adjoining a different endzone of the amplification region. In the latter, independent adjustment of the TE and TM amplification profiles is possible. <IMAGE></p>