公开(公告)号：AT535792T

公开(公告)日：2011-12-15

申请号：AT06743189

申请日：2006-02-16

Applicant: IBM

Inventor： DECUSATIS CASIMER ,  KUCHTA DANIEL ,  SCHAUB JEREMY

IPC: G01M11/00

Abstract: Techniques for measuring optical modulation amplitude (OMA) are disclosed. For example, a technique for measuring an OMA value associated with an input signal includes the following steps/operations. The input signal is applied to a photodetector, wherein the photodetector is calibrated to have a given responsivity value R, and further wherein the photodetector generates an output signal in response to the input signal. The output signal from the photodetector is applied to a radio frequency (RF) power meter, wherein the RF power meter measures the root mean squared (RMS) power value of the output signal received from the photodetector. The OMA value associated with the input signal is determined in response to the root mean squared (RMS) power value measured by the RF power meter. The OMA value may be determined as a function of a factor F derived from a relationship between an amplitude of a data signal and the RMS value of the data signal.

公开(公告)号：AT364903T

公开(公告)日：2007-07-15

申请号：AT05723468

申请日：2005-02-22

Applicant: IBM

Inventor： CHU JACK ,  DEHLINGER GABRIEL ,  GRILL ALFRED ,  KOESTER STEVEN ,  OUYANG QIGING ,  SCHAUB JEREMY

IPC: H01L31/101

Abstract: The invention addresses the problem of creating a high-speed, high-efficiency photodetector that is compatible with Si CMOS technology. The structure consists of a Ge absorbing layer on a thin SOI substrate, and utilizes isolation regions, alternating n- and p-type contacts, and low-resistance surface electrodes. The device achieves high bandwidth by utilizing a buried insulating layer to isolate carriers generated in the underlying substrate, high quantum efficiency over a broad spectrum by utilizing a Ge absorbing layer, low voltage operation by utilizing thin a absorbing layer and narrow electrode spacings, and compatibility with CMOS devices by virtue of its planar structure and use of a group IV absorbing material. The method for fabricating the photodetector uses direct growth of Ge on thin SOI or an epitaxial oxide, and subsequent thermal annealing to achieve a high-quality absorbing layer. This method limits the amount of Si available for interdiffusion, thereby allowing the Ge layer to be annealed without causing substantial dilution of the Ge layer by the underlying Si.