ASE Injection Research Articles

800 Gb/s (80 × 10 Gb/s) capacity WDM-PON based on ASE injection seeding.

We demonstrate and characterize 800 Gb/s capacity WDM-PON with an ASE injection seeding. Required total seed power at central office to feeder fiber is 16 dBm for 20 km upstream transmission of 80 channels. We investigate the maximum transmission length according to channels. The transmission length is limited to 39.7 km by intra-channel crosstalk induced by Rayleigh back-scattering, provided that the dispersion is compensated. Also, we investigate the allowable differential path length to evaluate the flexibility of the system.

DWDM-PON at 25 GHz channel spacing based on ASE injection seeding

We demonstrate a 25 GHz-channel-spaced DWDM-PON based on ASE injection seeding. A 60 km transmission at 1.25 Gb/s per channel is available with a 2nd generation FEC. The major limiting factor is the optical back reflection induced penalty. Thus a high gain reflective modulator and/or relocation of the seed light increase the transmission length. We demonstrated 90 km transmission with relocated seed light to remote node.

Broadcast/multicast transmission of video signal in a WDM-PON using a low-cost injection-locked F-P LD with broadband ASE

A broadcast/multicast transmission method in a WDM-PON system using a low-cost Fabry-Perot laser diode with broadband ASE injection is proposed and experimentally demonstrated in this paper. Because of its low front-facet reflectivity (∼0.1%), the F-P LD exhibits a broadband lasing spectrum and reduced mode-partition noise. To demonstrate its performance, the bit error rate and packet loss rate were measured. The proposed optical source provides a cost-effective WDM-PON architecture for a broadcast/multicast service accommodating more than 32×622MBps. For the transmission of MPEG-2 TS packets, zero packet loss could be obtained at an optical power of -32dBm.

Compromised extinction and signal-to-noise ratios of weak-resonant-cavity laser diode transmitter injected by channelized and amplitude squeezed spontaneous-emission

By using a 200GHz AWG channelized ASE source in connection with a saturable semiconductor optical amplifier (SOA) based noise blocker as the injecting source at the remote node in front of the local optical network units (ONUs), we demonstrate the spectrum-sliced ASE transmitter with greatly suppressed intensity noise performance in WDM-PON network. Such channelized SOA filtering technique effectively reduces the relative intensity noise of the ASE source by at least 4.5 dB. The low-noise WRC-FPLD transmitter improves its extinction-ratio (ER) from 8.9 to 9.6 dB and signal-to-noise ratio (SNR) from 5.9 to 6.3 dB. In comparison with broad-band ASE injection-locked WRC-FPLD transmitter at same power, there is an improvement on receiving power penalty (DeltaP(Receiver)) by 2 dB at BER 10(-9) in back-to-back case, and the receiving power of BER 10(-9) can achieve -24 dBm even after 25km fiber transmission. With additional AWG filtering, the intraband crosstalk effect between the upstream transmitted data and the reflected ASE signal is significantly reduced by 6.3dB. The compromised effects of ER and SNR on BER performance are also elucidated via the modified SNR model for the WRC-FPLD under ASE injection induced gain-saturation condition. The DeltaP(Receiver)/DeltaSNR of 8.89 at same ER condition is more pronounced than the DeltaP(Receiver)/DeltaER of 3.17 obtained under same SNR condition, indicating that the SNR plays a more important role than the ER on enhancing the BER performance.

Uncooled$C$-Band Wide-Band Gain Lasers With 32-Channel Coverage and$-$20-dBm ASE Injection for WDM-PON

We report a spectrum-sliced amplified spontaneous emission-injected wide-band gain laser covering a temperature range over 110/spl deg/C as well as entire 32 100-GHz-spaced channels (1533-1558 nm) in 155-Mb/s upstream transmissions over 25 km of single-mode fiber in a wavelength-division-multiplexed passive optical network. The wide-band gain laser diode employs asymmetric multiple quantum-well structure and low antireflection coating in order to widen the gain spectrum.

L-band all-optical gain-clamped EDFA by utilizing C-band backward ASE

By using an optical circulator and C/L-band wavelength division multiplexer to recycle the C-band backward ASE, an L-band gain-clamped erbium-doped fiber amplifier is presented. We have experimentally studied the static gain clamping property of this amplifier. As the ASE feedback attenuation is set to 0, the gain at 1585nm can be clamped at 18.84±0.26dB within dynamic range of 25dB and the critical power reaches about −15.09dBm. The gain variation and saturated output power at 1585nm for 0dB attenuation are 1dB lower and 2.17dB higher than those for 30dB attenuation, which indicates that the L-band EDFA gain can be effectively clamped via the ASE injection technique.

Effect of injection of C-band ASE on L-band erbium-doped fiber amplifier

The effect of injecting conventional band (C-band) amplified spontaneous emission on the performance of long-wavelength band erbium-doped fiber amplifier (L-band EDFA) is demonstrated. It uses a circulator and broadband fiber Bragg grating (FBG) to route C-band ASE from a C-band EDFA. Injection of a small amount of ASE (attenuation of 20 dB or above) improves the small signal gain with a negligible noise figure penalty compared to that of an amplifier without the ASE injection. A maximum gain improvement of 3.5 dB is obtained at an attenuation of 20 dB. At very large amounts of ASE injection (attenuation of 0 dB), the gain of the amplifier is clamped at 15.2 dB from −40 to −10 dBm with a gain variation of less than 0.3 dB. The saturation power is also increased from −8 dBm (for without ASE injection) to 2 dBm (VOA=0 dB) with a slight noise figure penalty. These results show that the ASE injection technique can be used either for gain improvement or for gain clamping in L-band EDFA.

Coupled structure for wide-band EDFA with gain and noise figure improvements from C to L-band ASE injection

We propose a novel structure for C plus L-band silica based wide-band erbium-doped fiber amplifiers (W-EDFA's), which use backward amplified spontaneous emission from the C-band EDFA as the pump-mediating injection source for the L-band amplifier unit. Experimental results show gain and noise figure improvements of over 2.6 dB and 0.6 dB, respectively, at -3.5 dBm of L-band input signal power. Spatially resolved numerical analysis confirms the pump-mediating effect of C-band backward ASE in the L-band EDFA for the gain and noise figure improvement, which also provides better understanding on the dynamics of C-band injection seed methods.