Prior art — US Patent 10404366

Relevant Prior Art for U.S. Patent 10,404,366

This analysis details the prior art cited during the prosecution of U.S. Patent 10,404,366. Each reference is examined for its potential to anticipate the claims of the patent under 35 U.S.C. § 102. The core of the invention in patent '366 is the use of different threshold values for different wavelength bands to control the insertion of dummy light in a wavelength-division multiplexing (WDM) system, particularly one with mixed signal grids.

The following prior art references were cited by the examiner during the patent's prosecution.

1. US 2014/0286635 A1 (Fujitsu Limited)

Full Citation: US Patent Application Publication No. US 2014/0286635 A1
Publication Date: September 25, 2014
Filing Date: March 25, 2013
Brief Description: This application describes an optical transmission apparatus that inserts dummy light to compensate for dropped or failed signal channels in a WDM system. It discloses monitoring the power of the multiplexed signal and, if a channel is lost, inserting dummy light with a power level equivalent to the lost signal to maintain stable operation of optical amplifiers. The system can set an upper limit on the number of dummy light channels that can be inserted.
Potential Anticipation of Claims: This reference is highly relevant as it addresses the same technical problem: maintaining constant optical power by inserting dummy light. It discloses monitoring optical signal intensity and controlling dummy light based on that monitoring. However, it does not appear to explicitly teach or suggest using a plurality of different threshold values assigned to different wavelength bands as required by independent claims 1 and 10 of patent '366. Instead, it seems to focus on replacing lost signals on a one-for-one basis or using a single power threshold for the entire WDM signal. Therefore, while it describes the general framework, it likely does not anticipate the specific limitation of using multiple, band-specific thresholds.

2. US 7,136,593 B1 (NEC Corporation)

Full Citation: US Patent No. 7,136,593 B1
Publication Date: November 14, 2006
Filing Date: June 16, 1999
Brief Description: This patent discloses a WDM optical transmission system that aims to maintain a constant total power level to avoid gain fluctuations in optical amplifiers when the number of active channels changes. It describes a system that monitors the number of input WDM signals and controls a supplementary light source (dummy light) to compensate for any decrease in signal count.
Potential Anticipation of Claims: This reference, from the original assignee of the '366 patent, establishes the foundational concept of using dummy light to stabilize amplifier gain. It discloses monitoring and control based on the presence or absence of signals. However, similar to the Fujitsu reference, it does not appear to describe the nuanced approach of assigning different power thresholds to different wavelength bands to make decisions about dummy light insertion. The control logic described is based on the number of channels rather than finely-tuned power measurements within specific, variable-threshold sub-bands. This makes it unlikely to anticipate the key elements of claims 1 and 10.

3. US 2008/0304829 A1 (Sato)

Full Citation: US Patent Application Publication No. US 2008/0304829 A1
Inventor: Yoshiro Sato (same as the inventor for '366)
Publication Date: December 11, 2008
Filing Date: June 11, 2007
Brief Description: This application from the same inventor describes a wavelength multiplex transmission apparatus that controls dummy light to stabilize optical amplifier performance. It discloses a system that monitors the state of individual optical signals and inserts dummy light if a signal is lost. The control mechanism aims to maintain the total input power to the optical amplifier.
Potential Anticipation of Claims: This earlier work by the same inventor lays the groundwork for the '366 patent. It deals with the same problem of dummy light control in WDM systems. The critical question for anticipation is whether it discloses the use of a plurality of threshold values including different threshold values assigned to different wavelength bands (as claimed in '366). The '366 patent appears to be an improvement or refinement of this earlier concept, specifically by introducing the idea of multiple, distinct thresholds for different spectral regions to accommodate mixed-grid signals. This reference likely describes a system with a more uniform thresholding approach, and thus would not fully anticipate claims 1 and 10 of the '366 patent.

4. US 2016/0112141 A1 (Infinera Corporation)

Full Citation: US Patent Application Publication No. US 2016/0112141 A1
Publication Date: April 21, 2016
Filing Date: October 15, 2014
Brief Description: This application relates to wavelocking for optical signals in an arbitrary grid WDM system. It discloses generating out-of-band tones to identify and lock the wavelengths of individual channels. While its primary focus is on frequency stabilization rather than power stabilization via dummy light, it involves detailed monitoring of the optical spectrum.
Potential Anticipation of Claims: This reference is less relevant to the core invention of dummy light insertion for power control. Its teachings on monitoring an "arbitrary grid" system are pertinent to the problem background of the '366 patent, which is designed to handle mixed-grid signals. However, the reference does not concern itself with controlling dummy light based on monitored intensities against multiple thresholds. Therefore, it does not anticipate the independent claims of the '366 patent.