Halliburton Energy Services, Inc.

Homi Phiroze Cooper

Marian Morys

Raj Pai

John Thomas

Wallace R Gardner

Carl Dodge

Alberto Quintero

In some embodiments, apparatus and systems, as well as methods, may operate to select from multiple optical detectors and/or multiple detector amplifiers to form combinations of detectors and amplifiers as part of an optical detection system. The selection may be based on minimizing noise equivalent power (NEP) of the optical detector or a combination of an optical detector and a detector amplifier over a desired temperature range. Additional apparatus, systems, and methods are disclosed.

Detector, preamplifier selection apparatus, systems, and methods

Optical detection apparatus () comprising an optical detector (), a detector amplifier (), and switching means, e.g., a multiplexer (), for dynamically selecting at least one of the optical detector or the detector amplifier by switching from among at least two alternative optical detectors and/or at least two detector amplifiers such as to minimize noise equivalent power (NEP) of a selected detector or combination of detector and amplifier under given operating conditions.

Improved communication systems and methods are disclosed. In one embodiment, a downhole communications system comprises a downhole transceiver and a surface transceiver. The surface transceiver receives a discrete multi-tone (DMT) modulated uplink signal from the downhole transceiver, and transmits a downlink signal to the downhole transceiver using a modulation method determined by the transceivers as communications are initiated. The downlink modulation methods supported by the surface transceiver may include DMT modulation and quadrature amplitude modulation (QAM). The modulation mode selection may be based on measured channel characteristics, on proposed data rates, or on other predetermined parameters. The uplink and downlink signals may be communicated over a shared transmission mode on multiconductor cable or wired pipe, and alternatively the uplink and downlink signals may be communicated over separate transmission modes.

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Houston, TX, United States of America

Homi Phiroze Cooper