Corning Incorporated

Clement Dowd Burton

Douglas W Hall

Jeffery Alan DeMeritt

An improved four-port dichroic WDM, for use in a multiwavelength, bi-directional optical amplifier, having a dichroic filter for substantially reflecting a first wavelength band input to the WDM to an output of the WDM for the first wavelength band and for substantially transmitting a second wavelength band input to the WDM to an output of the WDM for the second wavelength band, in which some of a first 3 dB wavelength in the first wavelength band is transmitted by the filter and some of a second 3 dB wavelength in the second wavelength band is reflected by the filter, includes another dichroic filter having a filter function different than the filter function of the WDM filter providing an insertion loss for the first or the second 3 dB wavelengths sufficient to reflect and transmit, respectively, substantially all of the first and second 3 dB wavelengths. Additional dichroic filters for suppressing 3 dB light are used to prevent Q-switching in an optical gain cavity in a multiwavelength, bi-directional optical amplifier formed by a reflection point in an optical path connected to the amplifier.

Device and method to supress Q-switching in an optical amplifying device

The amount of light coupled to an optical fiber from a laser diode is limited to a predetermined maximum power. A lens receiving the laser output is adjusted to maximize the power received at the core portion of the fiber endface. The power coupled to the fiber is then reduced to the predetermined power level by insertion of a polarizing or absorbing filter in the optical path. When a polarizing filter is employed, it is rotated until the predetermined power is coupled to the fiber. If a quarter wave plate is included, negative effects due to back reflections from the fiber end face into the laser diode can be eliminated.

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Elmira, NY, United States of America

Clement Dowd Burton