Widely-tunable chip-scaletransmitters and wavelength converters

Larry Coldren
2003 Integrated Photonics Research   unpublished
Widely-tunable lasers have gained much attention over the past few years as universal sources for dense WDM networks [1] . Interest in the dynamic networking capability enabled by such sources is also of continued interest, although the slow-down in the build out of the telecom infrastructure has slowed the introduction of such architectures. In this paper we will review the current status of InP-based integrated optical transmitters, which are monolithically integrated on a single chip and
more » ... r the full C or L-bands, and we will also give an update on the recent application of such devices within monolithically-integrated widely-tunable wavelength converters. Figure 1 shows a schematic of the transmitter chip. It includes the four-section sampled-grating DBR (SGDBR) laser, an integrated SOA, and an electro-absorption modulator (EAM[2]). A common quaternary waveguide extends throughout the entire device and quantum well gain layers are included at the laser gain and SOA sections. The modulator bias is varied across the 40 nm tuning range to enable efficient modulation across this entire range. Figure 2 shows the bit-error rate after transmission through 350 km of standard single-mode fiber for two different wavelengths. The average modulated output power is about 3dBm in this case. Light Out Front Mirror Gain Phase Rear Mirror SG-DBR Laser Amplifier EA Modulator MQW active regions Q waveguide Light Out Front Mirror Gain Phase Rear Mirror SG-DBR Laser Amplifier EA Modulator MQW active regions Q waveguide Figure 1. SGDBR laser with integrated SOA Figure 2. Bit-error-rate results after transmission and EAM. Inset gives SEM photo of device. through 350 km of standard fiber at 2.5 Gb/s. -3 -6 -9 -12 log(BER) -35 -34 -33 -32 -31 -30 -29 -28 Recieved Power (dBm) DP=2dB 2.5Gb/s 350km SMF 1530nm 1560nm These lasers can also be operated as CW sources for external modulators by simply setting the EAM for maximum transmission. The standard qualified Agility product is calibrated for 10 mW out in this case. Figure 3 shows results from reliability testing on this laser. The FIT rate is given both with and without 'mode control' in which the mirror currents can be updated over life [3] . 0.1
doi:10.1364/ipr.2003.imb1 fatcat:mnbulyapjjaevd7xflire5ijbi