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US 2003/0116695 A1Published application
Optical semiconductor module for detecting wavelength and light intensity
OwnerKenji Masuda, Makoto Satoinventors
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Abstract
An optical semiconductor module has a laser diode (LD) for emitting light, a first photo-diode (PD) and a second PD for receiving light emitted backward from the LD, and a wavelength filter which is disposed on a light path between the LD and the first PD and continuously changes the intensity according to wavelength of the light. A distance between the light receiving surface of the second PD and the LD is set so as to be equal to or shorter than a distance between an incident surface of the wavelength filter and the LD.
Claims9
An optical semiconductor module comprising:
- a laser diode for emitting light;
- a first photo-diode having a light receiving surface for receiving the light emitted by the laser diode;
- a wavelength filter having an incident surface, the wavelength filter being disposed on a light path between the laser diode and the first photo-diode, which continuously changes intensity of the light falling on the first photo-diode according to wavelength of the light;
- and
- a second photo-diode having a light receiving surface for receiving the light emitted by the laser diode, the second photo-diode being positioned such that a distance between the laser diode and the light receiving surface of the second photo-diode is equal to or shorter than a distance between the laser diode and the incident surface of the wavelength filter.
2 more elements
An optical semiconductor module comprising:
- a laser diode for emitting light;
- a first photo-diode having a light receiving surface for receiving the light emitted by the laser diode;
- a wavelength filter having an incident surface, the wavelength filter being disposed on a light path between the laser diode and the first photo-diode, which continuously changes intensity of the light falling on the first photo-diode according to wavelength of the light;
- a second photo-diode having a light receiving surface for receiving the light emitted by the laser diode;
- and
- a shade disposed between the first photo-diode and the second photo-diode and extending from the light receiving surface of the second photo-diode at least to the incident surface of the wavelength filter.
3 more elements
Dependencies are inferred from the claim text.