Abstract: A method for identifying the boundaries between sequences of rocks laid down in different depositional regimes. The approach used is to search, in well logs or seismic data, for a statistic characteristic of such regimes, and for breaks in that statistic. The preferred statistic used in the method of the present invention is the first moment of the power spectrum of the wavenumber of a suitable physical property as a function of depth. This statistic is calculated rapidly and with excellent depth resolution from the complex-valued autocorrelation function at its zero and unit lag values, respectively, and displayed as a single variable in black-and-white or color. The method of the present invention further includes manipulations that achieve the approximate conversion of the scale (and corresponding display) from its initial dependence on depth to one that is displayed as a function of geologic time.

Abstract: A method of de-multiplexing and a time division de-multiplexer (1) for optic signals is disclosed. A multiplexed optic signal (A) is delivered through a cavity of a multi-region semiconductor laser amplifier device (2). The clock component is extracted (6) and it is used to drive (7) the contacts (3,4) of the device (2) with activating signals so that there is an electronic response in each contact for one channel of the optic signal (A) only. Thus, separate electronic data channels are sensed by sense amplifiers (14). The de-multiplexer (1) thus both de-multiplexes and converts optic signals to electronic signals simultaneously.

Abstract: A method and circuit for generating controlled light signals from electronic data signals in a semi-conductor laser transmitter of the type having a stimulated emission cavity with at least two electrical input contacts determining corresponding separate cavity regions. Electronic data input signals are applied to each input contact to drive the associated cavity region above a stimulated emission threshold level to generate cross-coupled stimulated emission by interaction of each region with carriers of the other region or regions. The electronic data signals are varied to control optic intensity and frequency according to pre-defined characteristics of the cross-coupled stimulated emission.