Resonant-cavity infrared optoelectronic devices
Resonant-cavity infrared optoelectronic devices
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谐振腔红外光电器件
DOI：
10.1007/s11664-997-0213-6
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发表时间：
1997
影响因子：
2.1
通讯作者：
N. Magnea
中科院分区：
文献类型：
--
作者：
J. Pautrat;E. Hadji;Joël Bleuse;N. Magnea
CdxHg 1 −xTe化合物非常适合设计谐振微腔器件。事实上，这些化合物显示出随组成的带隙和折射率的广泛变化，而晶格参数几乎保持不变。在3-5微米范围内谐振的微腔已经通过分子束外延制备。发光二极管（LED）通过堆叠掺杂n型的下布拉格反射镜（10.5周期）和包含50 nm有源层（CdTe-HgTe伪合金）的名义上未掺杂的腔介质而获得。上镜是沉积在腔体上的金层，其是部分p型掺杂的。直接偏置下观察到的二极管发射，高达室温，在符合腔谐振模式（线宽8毫电子伏）。它比有源层的非均匀线宽（300 K时为60 meV）窄得多。方向性也更好。二极管的特性与温度的关系很小。也可以设计类似的装置来制造红外检测器，其活性层厚度相对于常规检测器减小。在谐振波长处的检测器效率可以增加接近腔精细度的因子。在下镜为16.5个周期，上镜为介质镜（ZnS/YF 3为7个周期）的情况下，可以制造出品质因数达到350的3.06 μm谐振腔。利用YAG微激光器将谐振腔在介质镜上泵浦，在谐振腔谐振处产生激光发射。在10 K时，激光阈值为45 kW/cm ~ 2，线宽仅为1.7meV。这些结果表明，有用的微腔的概念，用于设计新的设备，如LED或激光器，这可能是新的应用的基础上的碲镉汞化合物。
The CdxHg1−xTe compounds are well suited to the design of resonant microcavity devices. Indeed these compounds display a wide variation of bandgap and refractive index with composition, while the lattice parameter remains practically unchanged. Microcavities resonating in the 3–5 µm range have been prepared by molecular beam epitaxy. Light emitting diodes (LEDs) are obtained by stacking a lower Bragg mirror (10.5 periods) which is doped n-type and a nominally undoped cavity medium containing a 50 nm active layer (CdTe-HgTe pseudo-alloy). The upper mirror is a gold layer deposited on the cavity, which is partly p-type doped. The diode emission is observed under direct bias, up to room temperature, in coincidence with the cavity resonance mode (linewidth 8 meV). It is much narrower than the inhomogeneous linewidth of the active layer (60 meV at 300K). The directivity is also much better. The diode properties are only very slightly dependent on temperature. A similar device can also be designed to make an infrared detector whose active layer thickness is reduced with respect to conventional detectors. The detector efficiency at the resonance wavelength may be increased by a factor close to the cavity finesse. With 16.5 periods in the lower mirror and a dielectric mirror as upper mirror (seven periods of ZnS/YF3), it has been possible to make a cavity resonating at 3.06 µm whose quality factor reaches 350. By photopumping the cavity across the dielectric mirror with a YAG microlaser, a laser emission occurred at the cavity resonance. At 10K, the laser threshold is 45 kW/cm2 and the linewidth is only 1.7 meV. These results demonstrate the usefulness of the microcavity concept for designing new devices such as LED or lasers which could be the basis for new applications of CdHgTe compounds.