Optical transmitter, active optical cable, and optical transmission method
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
H04B-010/04
H04B-010/564
G02B-006/42
H04B-010/50
H01S-005/042
H04B-010/54
H01S-005/062
출원번호
US-0883279
(2018-01-30)
등록번호
US-10122469
(2018-11-06)
우선권정보
JP-2014-211226 (2014-10-15)
발명자
/ 주소
Kubo, Tatsuo
Kikuchi, Osamu
Tanaka, Takayuki
출원인 / 주소
FUJIKURA LTD.
대리인 / 주소
Westerman, Hattori, Daniels & Adrian, LLP
인용정보
피인용 횟수 :
0인용 특허 :
13
초록▼
A connector which serves as an optical transmitter in accordance with an embodiment of the present invention includes: a transmitting circuit configured to convert a data signal into an electric current signal, the data signal being a three-valued; and an LD configured to convert the electric curren
A connector which serves as an optical transmitter in accordance with an embodiment of the present invention includes: a transmitting circuit configured to convert a data signal into an electric current signal, the data signal being a three-valued; and an LD configured to convert the electric current signal into an optical signal. The transmitting circuit detects, as an IDLE interval, an interval during which the data signal falls within a predetermined range that is between a high level and a low level. The transmitting circuit controls, during the IDLE interval, the electric current signal to be not greater than a threshold electric current of the LD.
대표청구항▼
1. An optical transmitter, comprising: a modulation driver configured to draw in a modulation electric current in accordance with a data signal;an auxiliary driver configured to draw in or draw out an auxiliary electric current during a no-signal interval of the data signal; anda light emitting elem
1. An optical transmitter, comprising: a modulation driver configured to draw in a modulation electric current in accordance with a data signal;an auxiliary driver configured to draw in or draw out an auxiliary electric current during a no-signal interval of the data signal; anda light emitting element in or out which a driving electric current flows, the driving electric current resulting from subtracting the auxiliary electric current from a sum of or a difference between a bias electric current and the modulation electric current,the auxiliary electric current being set so that the driving electric current during the no-signal interval is not greater than a threshold electric current of the light emitting element. 2. The optical transmitter as set forth in claim 1, wherein: the auxiliary driver is configured to draw in the auxiliary electric current during the no-signal interval;the light emitting element is a light emitting element in which the driving electric current flows, the driving electric current resulting from subtracting the auxiliary electric current from the difference between the bias electric current and the modulation electric current; andthe auxiliary electric current is set so that a sum, during the no-signal interval, of the auxiliary electric current and the modulation electric current is not smaller than the bias electric current. 3. The optical transmitter as set forth in claim 2, wherein: the auxiliary electric current is set so that the sum, during the no-signal interval, of the auxiliary electric current and the modulation electric current is greater than the bias electric current; andthe optical transmitter further includes a compensating electric current source configured to draw out a compensating electric current which compensates for an insufficiency of the bias electric current, in a case where the sum of the modulation electric current and the auxiliary electric current exceeds the bias electric current. 4. The optical transmitter as set forth in claim 2, wherein: the data signal has a pattern composed of (i) a DATA interval during which the data signal is at a high level or a low level and (ii) an IDLE interval during which the data signal is kept at an intermediate level that is between the high level and the low level; andthe no-signal interval is the IDLE interval. 5. The optical transmitter as set forth in claim 4, wherein: the auxiliary driver includes (i) a pre-driver configured to amplify an IDLE detection signal indicative of the IDLE interval and (ii) a main driver configured to switch between drawing in the auxiliary electric current and not drawing in the auxiliary electric current, in accordance with the IDLE detection signal amplified by the pre-driver. 6. The optical transmitter as set forth in claim 5, wherein: the auxiliary driver further includes (i) a voltage dropping device provided between a power source and the pre-driver and (ii) a control circuit configured to control a voltage drop, caused by the voltage dropping device, in accordance with an output voltage of the pre-driver. 7. The optical transmitter as set forth in claim 1, wherein: the auxiliary driver is configured to draw out the auxiliary electric current during the no-signal interval;the light emitting element is a light emitting element out which the driving electric current flows, the driving electric current resulting from subtracting the auxiliary electric current from the sum of the bias electric current and the modulation electric current; andthe auxiliary electric current is set to be not smaller than the bias electric current. 8. The optical transmitter as set forth in claim 7, wherein: the auxiliary electric current is set to be greater than the bias electric current; andthe optical transmitter further includes a compensating electric current source configured to draw out a compensating electric current which compensates for an insufficiency of the bias electric current, in a case where the auxiliary electric current exceeds the bias electric current. 9. The optical transmitter as set forth in claim 1, wherein: the light emitting element is a cathode-grounded light emitting element in which the driving electric current flows, the driving electric current resulting from subtracting the auxiliary electric current from the difference between the bias electric current and the modulation electric current. 10. The optical transmitter as set forth in claim 3, wherein: the compensating electric current source includes a diode or transistor connected to a clamp power source and the light emitting element. 11. The optical transmitter as set forth in claim 8, wherein: the compensating electric current source includes a diode or transistor connected to a clamp power source and the light emitting element. 12. An active optical cable comprising: a cable which houses an optical fiber; anda pair of connectors provided at respective ends of the cable,one or both of the pair of connectors including an optical transmitter recited in claim 1. 13. An ONU (Optical Network Unit) constituting a PON (Passive Optical Network), comprising an optical transmitter recited in claim 1. 14. A method of transmitting light, comprising the steps of: (a) drawing in a modulation electric current in accordance with a data signal;(b) drawing in or drawing out an auxiliary electric current during a no-signal interval of the data signal; and(c) causing a driving electric current to flow in or out a light emitting element, the driving electric current resulting from subtracting the auxiliary electric current from a sum of or a difference between a bias electric current and the modulation electric current,the auxiliary electric current being set so that the driving electric current during the no-signal interval is not greater than a threshold electric current of the light emitting element.
Lee Robert P. (Woodstock NY) Closs Felix H. (Adliswil CHX), Method and means for demand accessing and broadcast transmission among ports in a distributed star network.
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