Inventor
OGUMA TAKEFUMI
JP18 patents
⚠️ This page may combine multiple inventors who share the name “OGUMA TAKEFUMI”. Patents are grouped by organization below to help distinguish them — per-person disambiguation is on the roadmap.
NEC CORP
12 patentsUS5936768AAug 10, 1999
Optical passive device for an optical fiber amplifier and the optical amplifier
NEC CORP25 citations92
US5880874AMar 9, 1999
Optical equalizer and optical amplifier and wavelength multiple optical transmission apparatus using optical equalizer
NEC CORP27 citations92
US7127183B2Oct 24, 2006
Output monitor/control apparatus and optical communication system
NEC CORP12 citations83
US6911627B2Jun 28, 2005
Heating element device, heating element mounted structure, temperature control circuit, temperature control apparatus, and module
NEC CORP10 citations73
US6597483B1Jul 22, 2003
Laser oscillation wavelength monitoring device
NEC CORP8 citations73
US11483067B2Oct 25, 2022
Optical time domain reflectometer, test method of optical transmission line, and test system of optical transmission line
NEC CORP5 citations67
US11476930B2Oct 18, 2022
Optical time domain reflectometer, method of testing optical transmission line, and test system of optical transmission line
NEC CORP3 citations67
US7389032B2Jun 17, 2008
Method and apparatus for adjusting loss caused by optical fiber curvature, and optical transmission system using the same
NEC CORP4 citations62
US6601401B2Aug 5, 2003
Temperature controller and light-waveguide with the same
NEC CORP0 citations51
US11626937B2Apr 11, 2023
Optical transmission apparatus and control method of optical transmission apparatus
NEC CORP0 citations49
US10659165B2May 19, 2020
Optical transmission device
NEC CORP0 citations49
US10539741B2Jan 21, 2020
Optical device with optical filters and processing method of optical signals
NEC CORP0 citations49
OGUMA TAKEFUMI
3 patentsUS8238745B2Aug 7, 2012
Collection of data from an optical channel monitor without causing a malfunction of a transmission apparatus
OGUMA TAKEFUMI2 citations59
US8879908B2Nov 4, 2014
Optical channel monitor
OGUMA TAKEFUMI1 citations49
US7649162B2Jan 19, 2010
Optical feedback control unit, optical communication system, feedback control method, and recording medium for recording program
OGUMA TAKEFUMI0 citations46