Optical composite module, optical wavelength multiplexer, optical wavelength demultiplexer, and optical composite module manufacturing method

An optical composite module that outputs light modulated by an inputted electric signal and multiplexes the modulated light and light having a plurality of wavelengths output from an input optical fiber for output to an output optical fiber, comprising:

• a light-emitting element for emitting the light modulated by the inputted electric signal;
• a collimator for converting the light emitted from the light-emitting element into collimated light;
• an optical filter that passes light of a predetermined range of wavelengths inputted from the collimator and reflects light outside of the predetermined wavelengths among light inputted thereinto, which is placed between the collimator and the input and output optical fibers;
• a first convergent rod lens placed between the optical filter and the input and output optical fibers for converting the light output from the input optical fiber into collimated light, inputting the converted light into the optical fiber, and focusing the collimated light reflected by the optical filter and the collimated light passing through the optical filter on an end of the output optical fiber;
• and
• a positioning component for coinciding an optical axis of the first convergent rod lens with a center line between the input optical fiber and the output optical fiber.

An optical composite module that outputs light modulated by an inputted electric signal and multiplexes the modulated light and light having a plurality of wavelengths output from an input optical fiber for output to an output optical fiber, comprising:

• a light-emitting element for emitting the light modulated by the inputted electric signal and focusing the emitted light on a single point;
• a first convergent rod lens for converting the light focused by the light-emitting element into collimated light traveling in parallel with an optical axis;
• an optical filter placed between the first convergent rod lens and the input and output optical fibers, the optical filter passing light of a predetermined range of wavelengths output from the first convergent rod lens and reflecting light outside of the predetermined wavelengths among light inputted thereinto;
• a second convergent rod lens placed between the optical filter and the input and output optical fibers, the second convergent rod lens converting the light output from the input optical fiber into collimated light for inputting into the optical filter, and focusing the collimated light reflected by the optical filter and the collimated light passing through the optical filter on an end of the output optical fiber;
• and
• a positioning component for coinciding an axis of the second convergent rod lens with an axis of the output optical fiber, wherein
• an interface surface between the optical filter and the second convergent rod lens is angled so that the collimated light reflected by the optical filter and the collimated light passing through the optical filter are focused on the end of the output optical fiber.

An optical composite module that outputs light modulated by an inputted electric signal and multiplexes the modulated light and light having a plurality of wavelengths output from an input optical fiber for output to an output optical fiber, comprising:

• a light-emitting element for emitting the light modulated by the inputted electric signal and focusing the emitted light on a single point;
• a first convergent rod lens for converting the light focused by the light-emitting element into collimated light traveling in parallel with an optical axis;
• an optical filter placed between the first convergent rod lens and the input and output optical fibers, the optical filter passing light of a predetermined range of wavelengths output from the first convergent rod lens and reflecting light outside of the predetermined wavelengths among light inputted thereinto;
• a second convergent rod lens placed between the optical filter and the input and output optical fibers, the second convergent rod lens converting light output from the input optical fiber into collimated light for inputting into the optical filter, and focusing the collimated light reflected by the optical filter and the collimated light passing through the optical filter on an end of the output optical fiber;
• and
• a positioning component for coinciding an axis of the second convergent rod lens with a center line between the input optical filter and the output optical fiber, wherein
• the optical filter is provided with an angled end facing the first convergent rod lens so that the collimated light from the first convergent rod lens is refracted and focused on the end of the output optical fiber.

An optical composite module that demultiplexes light having a plurality of wavelengths output from an input optical fiber for converting light of a predetermined range of wavelengths into an electric signal and outputting light outside of the predetermined wavelengths to an output optical fiber, comprising:

• an optical filter that passes the light falling within a predetermined range of wavelengths to be converted into the electric signal and reflects the light outside of the predetermined wavelengths;
• a first convergent rod lens placed between the input and output optical fibers and the optical filter, the first convergent rod lens converting the light output from the input optical fiber into collimated light for inputting into the optical filter, and focusing the collimated light reflected by the optical filter on an end of the output optical fiber;
• a second convergent rod lens for focusing the collimated light passing through the optical filter;
• a light-receiving element for receiving the light focused by the second convergent rod lens and converting the received light into the electric signal;
• and
• a positioning component for coinciding an optical axis of the first convergent rod lens with an axis of the input optical fiber, wherein
• an interface surface between the optical filter and the first convergent rod lens is angled so that the collimated light reflected by the optical filter is focused on the end of the output optical fiber.

An optical composite module that demultiplexes light having a plurality of wavelengths output from an input optical fiber for converting light of a predetermined range of wavelengths into an electric signal and outputting light outside of the predetermined wavelengths to an output optical fiber, comprising:

• an optical filter that passes the light falling within a predetermined range of wavelengths to be converted into the electric signal and reflects the light outside of the predetermined wavelengths;
• a first convergent rod lens placed between the input and output optical fibers and the optical filter, the first convergent rod lens converting the light output from the input optical fiber into collimated light for inputting into the optical filter, and focusing the collimated light reflected by the optical filter on an end of the output optical fiber;
• a second convergent rod lens for focusing the collimated light passing through the optical filter on a single point;
• a light-receiving element for receiving the light focused by the second convergent rod lens and converting the received light into the electric signal;
• and
• a positioning component for coinciding an optical axis of the first convergent rod lens with a center line between the input optical fiber and the output optical fiber.

An optical wavelength demultiplexer that receives a wavelength-multiplexed optical signal having a plurality of wavelengths and demultiplexes the received signal into optical signals on a wavelength basis, comprising:

• a wavelength demultiplexing section for demultiplexing the received wavelength-multiplexed optical signal into at least two or more wavelength bands;
• an optical signal demultiplexing section provided to each wavelength band for demultiplexing the optical signals in two or more wavelength bands into original optical signals on a wavelength basis, wherein
• the optical signal demultiplexer is provided with a plurality of optical composite modules including a light-receiving element that demultiplexes a portion of the inputted optical signals for converting the demultiplexed signal into an electric signal, and outputs other optical signals, wherein
• the plurality of optical composite modules are connected in series.

An optical wavelength multiplexer that wavelength-multiplexes optical signals having a plurality of wavelengths divided into at least two or more wavelength bands and outputs a wavelength-multiplexed signal, comprising:

• an optical signal multiplexing section provided to each wavelength band for multiplexing optical signals having a plurality of wavelengths included in the wavelength band and outputting a multiplexed signal as an optical signal in the wavelength band;
• and
• a wavelength band optical signal multiplexing section for multiplexing the optical signal in the wavelength band output from each optical signal multiplexing section for outputting, wherein
• the optical signal multiplexing section is provided with a plurality of optical composite modules including a light-emitting element that outputs an optical signal modulated by an inputted electric signal and multiplexes the modulated optical signal and an inputted optical signal for outputting, and
• the plurality of optical composite modules are connected in series.

An optical composite module manufacturing method for manufacturing an optical composite module that converts convergent light emitted from a light-emitting element into collimated light traveling in parallel with an axis and outputs the converted light, comprising:

• a process of removably inserting an optical fiber collimator into a split sleeve from one end thereof, the optical fiber collimator converting light output from an optical fiber whose axis coincides with the optical axis into collimated light traveling in parallel with the optical axis;
• a process of inserting a lens holder holding a convergent rod lens into the split sleeve from another end thereof;
• a process of fitting the lens holder into an alignment sleeve from an end thereof so as to allow the lens holder to be movable in a direction of an axis;
• a process of determining a position of the convergent rod lens so that an output from the optical fiber becomes maximized when the light-emitting element is emitting light;
• a process of securing the alignment sleeve and the lens holder, and securing the alignment sleeve and the light-emitting element at the position determined in the process of determining the position of the convergent rod lens;
• and
• a process of pulling out the optical fiber collimator inserted into the split sleeve after the securing process.

An optical composite module manufacturing method for an optical composite module that focuses inputted collimated light on a single point and inputs the focused light into a light-receiving element, comprising:

• a process of removably inserting an optical fiber collimator into a split sleeve from an end thereof, the optical fiber collimator converting light output from an optical fiber whose axis coincides with the optical axis into collimated light traveling in parallel with the optical axis;
• a process of inserting a lens holder holding a convergent rod lens into the split sleeve from another end thereof;
• a process of inserting the lens holder into an alignment sleeve from an end thereof so as to allow the lens holder to be movable in a direction of an axis;
• a process of determining a position of the convergent rod lens so that an output from the light-receiving element becomes maximized when light is output from the optical fiber;
• a process of securing the alignment sleeve and the lens holder, and securing the alignment sleeve and the light-receiving element at the position determined in the process of determining the position of the convergent rod lens;
• and
• a process of pulling out the optical fiber collimator inserted into the split sleeve after the securing process.