100 Gb/s and 2 V V _π InP Mach‐Zehnder modulator with an n‐i‐p‐n heterostructure

Abstract

An ultra-high bandwidth (BW) and a low V π InP Mach-Zehnder modulator with an n-i-p-n heterostructure is proposed. The combination of the n-i-p-n heterostructure and the capacitive-loaded travelling-wave electrode provides a modulator with extremely low electrical loss. The device exhibits a 3 dB electro-optic BW of over 67 GHz and a V π of 2.0 V. A 100 Gb/s non-return-to-zero on-off keying modulation with an extinction ratio of over 10 dB is also realised.

Silicon-organic hybrid (SOH) modulators for intensity-modulation / direct-detection links with line rates of up to 120 Gbit/s

“…While this device exploits the Pockels effect in the EO polymer to provide a negligible chirp parameter of α = −0.02, it still features a large length in excess of 6 mm, dictated by the comparatively low EO coefficient of r 33 = 86 pm/V as well as by the rather large optical mode field and the associated spacing of the microstrip transmission line electrodes. The device length can be slightly reduced to approximately 4 mm by using high-speed InP-based MZM [9,10]. These devices, however, still have rather high voltage-length products of more than 5 Vmm [11], and rely on fabrication processes that are rather expensive and limited in scalability as compared to CMOS-based silicon photonic integration.…”

“…These devices, however, suffer from an inherent tradeoff between insertion loss and operation voltage [19], requiring peak-to-peak voltage swings of 8 V pp that become effective when applying a 4 V pp drive signal to an unterminated MZM [18]. In addition, with the exception of the all-polymer device [7,8], all signaling experiments of high-speed MZM have relied on drive signals generated by benchtop-type laboratory test equipment [9,10,18,20]. The associated electronic circuits feature high power consumption and are unsuited for integration into small form-factor packages.…”

Silicon-Organic Hybrid (SOH) Mach-Zehnder Modulators for 100 Gbit/s on-off Keying

“…The 100 Gbit/s achieved in our experiment corresponds to the highest OOK data rate generated by a silicon-based modulator so far, see Section “Competitive benchmarking and application potential” for a more detailed comparison to other experiments. Note that in our as well as in competing high-speed OOK demonstrations 10 , 11 , 18 , the data rate of 100 Gbit/s does not refer to the net data rate, but to the line rate and hence includes the 7% FEC overhead.…”

“…( c ) Modulus and phase of measured small-signal electro-optic frequency response of a 1.1 mm long SOH MZM. Note that the bandwidth of an EO modulator is usually specified by the modulation frequency which corresponds to a 6 dB drop of EOE response 10 , 57 . For the spectral component associated with the modulation frequency, this corresponds to a drop of the optical power and hence of the photocurrent amplitude by factor of two, which is measured as a four-fold (6 dB) decrease of the spectral power density by the VNA.…”

“…In this context, the key challenge is to build transmitters that can generate 100 Gbit/s OOK data streams at lowest possible power consumption, and such transceivers have even been identified as the “Holy Grail” of the Ethernet ecosystem by the Ethernet Alliance 7 . In fact, while a wide variety of compact high-speed optical modulators has been demonstrated over the last years 8 – 18 , only a few 10 , 11 , 14 , 18 are at all capable of providing OOK data rates of 100 Gbit/s, and these often feature comparatively high operating voltages. When it comes to high-speed Mach-Zehnder modulators (MZM), the most efficient 100 Gbit/s device demonstrated so far is based on 2.5 mm-long phase shifters and features a π-voltage of 2 V 11 .…”