TY - JOUR
T1 - Correction
T2 - 47.5 ghz membrane-iii-v-on-si directly modulated laser for sub-pj/bit 100-gbps transmission (Photonics, (2021), 8, 31, 10.3390/photonics8020031)
AU - Diamantopoulos, Nikolaos Panteleimon Pandelis
AU - Yamaoka, Suguru
AU - Fujii, Takuro
AU - Nishi, Hidetaka
AU - Takeda, Koji
AU - Tsuchizawa, Tai
AU - Kakitsuka, Takaaki
AU - Matsuo, Shinji
N1 - Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/10
Y1 - 2021/10
N2 - Error in Figure In the original article [1], there was a mistake in Figure 5c,d as published. The mistake was in the x-axis of the shown eye diagrams, and it was due to a coding error in the MATLAB plotting function that was used. The symbol rate in this work was 60 GBaud. This corresponds to a pulse duration of T = 1/60 GHz ≈ 16.67 ps. Since the x-axis in eye diagrams is commonly between 0 and 2T, the correct x-axis should have been 0~33.33 ps instead of 0~16.67 ps (previously). Another way to confirm the mistake is by noticing that, if 2T ≈ 16.67 ps was assumed, that should have corresponded to a symbol rate of 120 GBaud (instead of 60 GBaud). This is obviously not the case, and such high-speed modulation was never claimed in this work. The corrected Figure 5c,d appear below. The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. The original article has been updated. Figure 5. 60 GBaud PAM-4 signal evaluation: (a) Experimental setup; (b) Bit-error rate (BER) versus received optical power at back-to-back (BTB) and after 2-kmSSMF transmissions, and (c,d) Eye diagrams after equalization. Measurements were performed at 25°C (I_b = 9.1 mA) and 50 °C (I_b = 15.1 mA).
AB - Error in Figure In the original article [1], there was a mistake in Figure 5c,d as published. The mistake was in the x-axis of the shown eye diagrams, and it was due to a coding error in the MATLAB plotting function that was used. The symbol rate in this work was 60 GBaud. This corresponds to a pulse duration of T = 1/60 GHz ≈ 16.67 ps. Since the x-axis in eye diagrams is commonly between 0 and 2T, the correct x-axis should have been 0~33.33 ps instead of 0~16.67 ps (previously). Another way to confirm the mistake is by noticing that, if 2T ≈ 16.67 ps was assumed, that should have corresponded to a symbol rate of 120 GBaud (instead of 60 GBaud). This is obviously not the case, and such high-speed modulation was never claimed in this work. The corrected Figure 5c,d appear below. The authors apologize for any inconvenience caused and state that the scientific conclusions are unaffected. The original article has been updated. Figure 5. 60 GBaud PAM-4 signal evaluation: (a) Experimental setup; (b) Bit-error rate (BER) versus received optical power at back-to-back (BTB) and after 2-kmSSMF transmissions, and (c,d) Eye diagrams after equalization. Measurements were performed at 25°C (I_b = 9.1 mA) and 50 °C (I_b = 15.1 mA).
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U2 - 10.3390/photonics8100407
DO - 10.3390/photonics8100407
M3 - Comment/debate
AN - SCOPUS:85116415086
SN - 2304-6732
VL - 8
JO - Photonics
JF - Photonics
IS - 10
M1 - 407
ER -