JPH05323214A - Step switching type light attenuator - Google Patents

Abstract

PURPOSE:To obtain a light attenuator which has good operability and in applied to the automatic measurement of an optical communication system by providing, for example, push buttons, etc., as a means for inserting and removing a light attenuation medium. CONSTITUTION:The light attenuator consists of light attenuating elements ATT1- ATTn corresponding to the push buttons BT1-BTn and rod lenses SL1.2 corresponding to optical connectors CN1.2. The light OPT inputted from the optical connector CN1 passes through the rod lens SL1 to reach the light attenuators ATT1-ATTn, where the light is attenuated by a certain quantity. Those light attenuating elements ATT2-ATTn are inserted or removed with the push buttons BT1-BTn. The attenuated light OPT passes through the rod lens SL2 and outputted from the optical connector CN2. Thus, the operation of the push buttons or one rotary dial, UP/DOWN key operation, and an attenuation quantity display unit are employed to improve the operability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a step switching type optical attenuator for optical communication.

[0002]

2. Description of the Related Art An optical attenuator is a device that gives a certain amount of attenuation to light intensity. Optical attenuators are roughly classified into two types. A fixed attenuator and a variable attenuator.

Fixed attenuators provide a fixed amount of attenuation.

The variable attenuator is used by changing the amount of attenuation continuously or stepwise.

The present invention relates to a step-switching type optical attenuator in which a dimming element that gives a certain amount of attenuation is replaced to change the amount of attenuation stepwise.

[0006]

The step-switching type optical attenuator having the conventional configuration has a problem that it is necessary to replace the dimming element when setting a required attenuation amount, which is troublesome.

It is an object of the present invention to provide a step switching type optical attenuator which eliminates the above-mentioned problems and has good operability.

[0008]

In order to achieve the above object, the present invention provides a push-button mechanically interlocking with an optical attenuation medium as a means for inserting / removing the optical attenuation medium in a step switching type optical attenuator. It is characterized in that means for electrically inserting / removing the optical attenuation medium is provided.

[0009]

1 to 10 show an embodiment of the present invention.

FIG. 1 is a diagram showing the principle of the present invention.

Optical attenuation elements (ATT _{1 to} ATT _n ) corresponding to the push buttons (BT _{1 to} BT _n ) and an optical connector (CN).
_The rod lenses (SL _1,2 ) corresponding to _{1, 2} ) are arranged as shown in the figure.

The light (OPT) input from the optical connector (CN ₁ ) reaches the optical attenuation elements (ATT _{1 to} ATT _n ) via the rod lens (SL ₁ ). Light here (OP
T) undergoes a certain amount of attenuation. Optical attenuator (ATT ₁ ~
ATT _n ) is inserted or removed by push buttons (BT _{1 to} BT _n ).

The attenuated light (OPT) is output from the optical connector (CN ₂ ) via the rod lens (SL ₂ ).

In FIG. 1, ATT ₁ , ATT ₄ , ATT _n
Is in the inserted state and ATT ₂ and ATT ₃ are in the removed state.

FIG. 2 is a diagram showing an operation example of the optical attenuator (ATT _1-n ) driven by the optical attenuator drive unit (ATD). FIG. 2A shows the case _where all the ATTs of ATT ₁ to ATT _n are inserted. The state where the maximum amount of attenuation is given is shown. FIG. 2B shows the case where ATT ₁ and ATT ₄ are inserted. FIG. 2C shows all ATs of ATT ₁ to ATT _n .
When T is removed, that is, the through state (attenuation amount = 0 dB) is shown.

FIG. 3 is an external view of the first embodiment of the present invention. In the first embodiment of the present invention, as a means for changing the attenuation amount, push buttons (BT ₁ to
It is an optical attenuator (OAT) having BT _n ). By manually pressing this push button, the damping element (ATT ₁
~ ATT _n ) is inserted to obtain a predetermined attenuation amount. Here, OPT indicates light, and CN ₁ and CN ₂
Indicates an input / output connector.

4 and 5 relate to a second embodiment of the present invention. The second embodiment is an optical attenuator driver (AT
D) An optical attenuator drive for inserting / removing an operation panel (PB) for setting the attenuation amount, an indicator (DSP) for displaying the attenuation amount, a control circuit (CONT), and optical attenuation elements (ATT _{1 to} ATT _n ). It is composed of a circuit (DRC). The operation sets the required attenuation on the operation panel. The output of the operation panel corresponding to the set attenuation amount is the control circuit (CO
NT). The control circuit decodes the input and outputs a drive signal to the optical attenuator drive circuit. The optical attenuator drive circuit amplifies the drive signal, and the optical attenuator (A
TT _{1 to} ATT _n ) are inserted and removed.

On the other hand, a display signal corresponding to the set attenuation amount is output to the display (DSP). The display shows the set attenuation.

When a predetermined amount of attenuation is set from the outside, if a setting signal is input from the external drive input terminal, the same operation as from the operation panel becomes possible.

FIG. 5 is an external view of the second embodiment.

6 to 9 relate to a third embodiment of the present invention. It is an optical attenuator capable of setting a predetermined amount of attenuation with a variable resistor (VR). The optical attenuator driver (ATD) is driven by a variable resistor (V
R), an analog / digital converter (ADC), a display, and an optical attenuator drive circuit. FIG. 6 shows the block diagram.

The resistance value of the variable resistor (VR) is changed by rotating the dial (VRD) with a predetermined attenuation amount.
The output (VC) of the variable resistor (VR) changes accordingly. The output voltage (VC) is converted into digital signals (O _{1 to} O ₄ ) by an analog / digital converter (ADC). FIG. 8 shows an example of the relationship between the ADC output (O _{1 to} O ₄ ) and the light attenuation amount.

FIG. 9 shows an example of the relationship between the output (VC) of the variable resistor and the amount of optical attenuation. FIG. 8 is an external view of the third embodiment.

The fourth embodiment of the present invention is "DOWN""S".
It is an optical attenuator that can set a certain amount of attenuation by operating the keys "TOP" and "UP". The external view is shown in FIG.

In the embodiment used in the above description, the passive optical attenuation elements (ATT _{1 to} ATT _n ) are used as the optical attenuation elements (ATT _{1 to} ATT _n ).
A part of the light is absorbed, a part of the light is reflected, and a part of the light is shielded spatially), but other elements that change the optical attenuation due to the electro-optic effect are used to eliminate mechanical operation. It is also possible.

[0026]

As described in detail above, according to the present invention, the operability is improved by the operation by the push button or one rotary dial or the UP / DOWN key operation and the display (displaying the attenuation amount). An optical attenuator can be realized.

Further, if a signal is externally supplied to the optical attenuator drive unit, it can be applied to automatic measurement of an optical communication system.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a diagram showing an operation example of optical attenuator elements (ATT _{1 to} ATT _n ) driven by an optical attenuator drive unit (ATD).

FIG. 3 is an external view of the first embodiment of the present invention.

FIG. 4 is a block diagram of a second embodiment of the present invention.

FIG. 5 is an external view of a second embodiment of the present invention.

FIG. 6 is a block diagram of a third embodiment of the present invention.

FIG. 7 is an external view of a third embodiment of the present invention.

8 is an analog / digital converter (A in FIG.
An example of the relationship between the output of DC) and the amount of attenuation is shown.

9 is an output (V of the variable resistor (VR) in FIG.
C) An example of the relationship between the amount of attenuation and the amount of attenuation is shown.

FIG. 10 is an external view of a fourth embodiment of the present invention.

[Explanation of symbols]

CN _1,2 Optical connector BT _1-n Push button OAT Optical attenuator OPT Optical S _1-n switch MD _1-n Electromagnetic drive circuit ATD Optical attenuator drive section SL _1-n Rod lens ATT _1-n Optical attenuator PB Operation panel DSP Display CONT Control circuit DRC Optical attenuator drive circuit VR Variable resistor VC Variable resistor output ADC Analog-digital converter

Claims (9)

[Claims] 1. A light-attenuating medium is provided in the middle of an optical path, and a push button mechanically interlocking with the light-attenuating medium is provided as means for changing the attenuation amount of the light-attenuating medium. Step switching optical attenuator. 2. A step-switching type optical attenuation, comprising one or a plurality of optical attenuation media in the optical path, and an electric drive circuit as a means for changing the attenuation amount of the optical attenuation media. vessel. 3. The step switching type optical attenuator according to claim 1, wherein the attenuation amount of the optical attenuation medium is given a binary weight. 4. The step switching type optical attenuator according to claim 2, further comprising a push button switch as an electric drive circuit and an electromagnetic drive circuit electrically controlled by the push button switch. 5. The electric drive circuit is controlled by the output of an up / down counter.
The step-switching optical attenuator described in. 6. An electric drive circuit having a variable resistor for generating a continuous voltage and an analog / digital converter for converting an analog voltage output of the variable resistor into a digital signal. 2. The step switching type optical attenuator described in 2. 7. The step-switching type optical attenuator according to claim 2, wherein an optical attenuating medium controlled by an electric drive circuit is used which changes the optical attenuating amount by an electro-optical effect. 8. The step switching type optical attenuator according to claim 2, wherein the electric drive circuit is provided with means for displaying an attenuation amount. 9. The step switching type optical attenuator according to claim 2, wherein an external control signal input terminal is provided in the electric drive circuit.