Tunable OTDR Based on Direct Modulation of Self-Injection-Locked RSOA for In-Service Monitoring of WDM-PON

Thollabandi, Madhan; Kim, Tae‐Young; Hann, Swook; Park, Chang‐Soo

doi:10.1109/lpt.2008.926928

Cited by 20 publications

(14 citation statements)

References 9 publications

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“…However, many of them were designed with only one stopband [2][3][4][5]. Dual stopbands UWB antenna is relatively scant [6][7][8][9]. A more recently reported antenna has been designed by making use of two split resonant rings (SRR) to obtain dual stopbands [9].…”

Section: Resultsmentioning

confidence: 99%

“…The RSOA is self-injection locked by the individual grating and acts as a multi-wavelength source. The available wavelength peaks are determined by the gain bandwidth of the ROSA (C band, 30 nm), the optical power necessary for multiple locking, the pass band of the FBGs, and the wavelength spacing between the FBGs [6,7]. The central wavelength of an optical signal can easily be changed by adjusting the Bragg wavelength of the FBGs, which allows changes to the wavelength spacing between optical peaks.…”

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confidence: 99%

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A tunable photonic microwave notch filter using a multiple wavelength optical source

Choi¹,

Jeon²,

Kim³

et al. 2009

Micro & Optical Tech Letters

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at 3.8 GHz is clearly observed, which gives about À33 dB rejection. At the rejection band of 2.3-12 GHz, the rejection of the transmission is less than about À20 dB. In Figure 5, the simulated result is in well agreement with the measured result. In Figure 6, the measured result of the proposed LPF provides better rejection characteristics than that of the conventional one whose size is 38.3 Â 25 mm 2 . CONCLUSIONSA compact LPF for wideband rejection is discussed and its brief design procedure is also described. DSISS and BDGS may yield slow wave effect, which can be resulted in small circuit size, sharp cutoff, and wide band rejection characteristics compared with the conventional LPF using SISS and CDGS. The size reduction of the proposed LPFs is about 23% compared with the conventional LPF. The proposed LPF is obtained in wideband rejection that is below À20 dB from 2.3 to 12 GHz. Photonic microwave filters (PMFs) have attracted a great deal of research interest recently because of their ability to allow the processing of radio frequency signals in the optical domain while maintaining the advantages of wide bandwidth, immunity to electromagnetic interference (EMI), and low loss [1][2][3]. They can be used in a wide range of radar applications and wireless communications. Generally, PMFs have been implemented based on the concept of a digital filter, in which the output is produced by summing the delayed components of the input signal with an individually assigned coefficient. The filter characteristic therefore depends on the number of optical sources being used and the available coefficients. To implement high quality multi-tap filters, then, several optical sources are required, increasing the system cost. For this reason, spectrum-sliced optical sources using the amplified spontaneous emission noise of an erbiumdoped fiber (EDFA) [4] and a broad band super-luminescent LED (SLED) [5] have been implemented to reduce the filter cost. These methods, however, are limited in their tuning range, notch dip, and modulation frequency.In this respect, we propose and experimentally demonstrate a tunable photonic microwave notch filter using a reflective semiconductor optical amplifier (RSOA) together with fiber Bragg gratings (FBGs) with no additional high cost optical source. The RSOA is self-injection locked by the individual grating and acts as a multi-wavelength source. The available wavelength peaks are determined by the gain bandwidth of the ROSA (C band, 30 nm), the optical power necessary for multiple locking, the pass band of the FBGs, and the wavelength spacing between the FBGs [6,7]. The central wavelength of an optical signal can easily be changed by adjusting the Bragg wavelength of the FBGs, which allows changes to the wavelength spacing between optical peaks. In our proposed tunable notch filter, we used a fixed FBG and a tunable FBG (TFBG), making the desired free spectral ranges (FSRs) with the deep notches of more than 35 dB obtainable by adjusting the wavelength spacing. PRINCIPLE OF THE FILTER OPE...

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

A tunable photonic microwave notch filter using a multiple wavelength optical source

Choi¹,

Jeon²,

Kim³

et al. 2009

Micro & Optical Tech Letters

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“…Optical time-domain reflectometry (OTDR), a conventional technique for fault detection in a single link, has difficulties to diagnose the WDM-PON due to the use of a fixed wavelength probe light. To solve this problem, researchers have proposed tunable OTDR by using wavelength-tunable laser pulse [4]- [6]. Various tunable sources have been exploited, such as commercial tunable laser [4], Fabry-Perot (FP) laser diode [5], and self-injection-locked semiconductor optical amplifier [6].…”

Section: Introductionmentioning

confidence: 99%

“…To solve this problem, researchers have proposed tunable OTDR by using wavelength-tunable laser pulse [4]- [6]. Various tunable sources have been exploited, such as commercial tunable laser [4], Fabry-Perot (FP) laser diode [5], and self-injection-locked semiconductor optical amplifier [6]. However, the tradeoff between spatial resolution and measurable range exists in pulse OTDR.…”

Section: Introductionmentioning

confidence: 99%

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Precise Fault Location in WDM-PON by Utilizing Wavelength Tunable Chaotic Laser

Wang

Yang

et al. 2012

J. Lightwave Technol.

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We propose a method to locate precisely faults in wavelength-division-multiplexing (WDM) passive optical network (PON) by using a wavelength tunable chaotic laser. The chaotic laser consists of a multiple-longitudinal-mode Fabry-Perot (FP) laser diode whose modes match the channels of WDM-PON, and an optical feedback loop including a filter. The loop feeds a proportion of light of one mode that passes through the filter back into laser cavity to generate chaotic light. By adjusting the filter frequency, we can tune the wavelength of the chaotic light, and diagnose the corresponding branch of WDM-PON. We demonstrate a proof-of-concept experiment for detection of three ITU channels. Fault location is realized by correlating the back-reflected light with its time-delayed duplicate. The results show that spatial resolution of 2 cm and dynamic range of about 20.8dB can be achieved. In addition, we have experimentally studied the effects of the strength level and wavelength mismatching of the feedback light on the chaotic output of the FP laser.Index Terms-Chaos, fault location, optical time domain reflectometry, passive optical networks, semiconductor lasers, wavelength division multiplexing.

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Fault location for WDM‐PON using a multiple‐longitudinal‐mode laser modulated by chaotic wave

Wang

Zhang

et al. 2015

Micro & Optical Tech Letters

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We experimentally demonstrate a cost‐effective method to locate faults in wavelength‐division‐multiplexing passive optical network (WDM‐PON) utilizing a multiple‐longitudinal‐mode Fabry–Perot semiconductor laser directly modulated by chaotic wave from a Colpitts oscillator. Due to chaos modulation, every longitudinal mode of the laser has chaotic intensity waveform. Using a tunable optical filter selects a mode to detect the wavelength‐matched branch of WDM‐PON using chaos correlation technique. Experimental results show that the unterminated fiber end, mismatch connector and fiber breakpoint can be preciously located. A detection range of approximately 75 km and a range‐independent spatial resolution of 14 cm are achieved. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2502–2506, 2015

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Tunable OTDR Based on Direct Modulation of Self-Injection-Locked RSOA for In-Service Monitoring of WDM-PON

Cited by 20 publications

References 9 publications

A tunable photonic microwave notch filter using a multiple wavelength optical source

A tunable photonic microwave notch filter using a multiple wavelength optical source

Precise Fault Location in WDM-PON by Utilizing Wavelength Tunable Chaotic Laser

Fault location for WDM‐PON using a multiple‐longitudinal‐mode laser modulated by chaotic wave

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