Wavelength multiplexed light transfer unit and wavelength multiplexed light transfer system

• US 5,793,908 A
• Filed: 07/26/1996
• Issued: 08/11/1998
• Est. Priority Date: 08/24/1995
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Mizuochi, Takashi, Kitayama, Tadayoshi
• Primary Examiner(s): Palmer, Phan T. H.
• Application Number:
  US08/687,734
• Time in Patent Office: 746 Days
• Field of Search: 385/24, 385/15, 385/16, 385/20, 385/31, 359/124, 359/127, 359/114, 359/115, 359/891
• US Class Current: 385/24
• CPC Class Codes: G02B 6/02085 characterised by the grating profile, e.g. chirped, apodised, tilted, helical
• CPC Class Codes: G02B 6/02138 based on illuminating a phase mask
• CPC Class Codes: G02B 6/29317 Light guides of the optical fibre type
• CPC Class Codes: G02B 6/29353 with a wavelength selective element in at least one light guide interferometer arm, e.g. grating, interference filter, resonator
• CPC Class Codes: G02B 6/29355 Cascade arrangement of interferometers
• CPC Class Codes: G02B 6/29358 Multiple beam interferometer external to a light guide, e.g. Fabry-Pérot, etalon, VIPA plate, OTDL plate, continuous interferometer, parallel plate resonator G02B6/29347, G02B6/29349, G02B6/2935, G02B6/29361 take precedence; resonator evanescently coupled to light guide G02B6/29335
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 14/0205 Select and combine arrangements, e.g. with an optical combiner at the output after adding or dropping
• CPC Class Codes: H04J 14/0206 Express channels arrangements
• CPC Class Codes: H04J 14/0213 Groups of channels or wave bands arrangements
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant

Abstract

A branch circuit is formed by forming an optical filter by means of connecting a wavelength selective reflector to between two units of directional coupler and further assembling three units of the optical filter. In the branch circuit, the three optical filters are connected to each other so that the light coming in from a first optical filter is outputted to a third optical filter when the wave length selective reflector reflects the light, and to a second optical filter when the wavelength selective reflector passes the light therethrough; the light coming in from the second optical filter is outputted to the first optical filter when the wavelength selective reflector reflects the light, and to the third filter when the wavelength selective reflector passes the light therethrough; and also the light coming in from the third optical filter is outputted to the second optical filter when the wavelength selective reflector reflects the light and to the first optical filter when the wavelength selective reflector passes the light therethrough.

Claims

1. A wavelength multiplexed light transfer unit comprising:

a first optical filter having a first terminal for receiving a light signal having a specified wavelength λ

2 as well as a light signal having a wavelength other than the wavelength λ

2, a second terminal for outputting the light signal having a wavelength λ

2 inputted into said first terminal, a third terminal for outputting a light signal having a wavelength other than the wavelength λ

2 inputted into said first terminal;

a second optical filter having a fourth terminal for receiving the light signal having a wavelength other than the wavelength λ

2 outputted from the third terminal of said first optical filter, a fifth terminal for receiving the light signal having the specified wavelength λ

2, and a sixth terminal for outputting the light signal having a wavelength other than the wavelength λ

2 inputted into said fourth terminal as well as a transmitted light signal having a wavelength λ

2 inputted into said fifth terminal,

a third optical filter having a seventh terminal for receiving a light signal having a specified wavelength λ

1 as well as a light signal having a wavelength other than the wavelength λ

1, an eighth terminal for outputting the light signal having a specified wavelength λ

2 as well as a light signal having a wavelength λ

1 inputted into said seventh terminal, a ninth terminal for receiving a light signal having a wavelength λ

2 outputted to said eighth terminal, and a tenth terminal for outputting a light signal having a wavelength other than the wavelength λ

1 received from said seventh terminal; and

a fourth optical filter having a twelfth terminal for receiving the light signal having a wavelength other than the wavelength λ

1 outputted from the tenth terminal of said third optical filter, a thirteenth terminal for receiving the light signal having the specified wavelength λ

1 as well as the light signal having a specified wavelength λ

2, a fourteenth terminal for outputting the light signal having a wavelength λ

1 received from said thirteenth terminal as well as a light signal having a wavelength other than the wavelength λ

1 received from said twelfth terminal, and an eleventh terminal for outputting the light signal having a wavelength λ

2 received from said thirteenth terminal;

wherein said second terminal and said eleventh terminal are connected to each other, and said fifth terminal and said ninth terminal are connected to each other.