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High channel count and high precision channel spacing multi-wavelength laser array for future PICs.

Shi Y, Li S, Chen X, Li L, Li J, Zhang T, Zheng J, Zhang Y, Tang S, Hou L, Marsh JH, Qiu B - Sci Rep (2014)

Bottom Line: In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost.In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch.As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%.

View Article: PubMed Central - PubMed

Affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Microwave-Photonics Technology Laboratory, Nanjing University, Nanjing, 210093, China.

ABSTRACT
Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%.

No MeSH data available.


(a) The lasing wavelengths of 6 laser arrays with wavelength spacing of 0.8 nm. (b) The maximum wavelength differences for the 15 channels of the 6 randomly selected laser arrays. The mean value is 0.788 nm (±0.394 nm) and standard deviation is 0.222 nm.
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f5: (a) The lasing wavelengths of 6 laser arrays with wavelength spacing of 0.8 nm. (b) The maximum wavelength differences for the 15 channels of the 6 randomly selected laser arrays. The mean value is 0.788 nm (±0.394 nm) and standard deviation is 0.222 nm.

Mentions: Absolute wavelength accuracy is another key parameter that must be evaluated. We randomly selected 6 laser array bars with 15 wavelengths, for which the same wavelength spacing of 0.8 nm was obtained, as shown in Fig. 5(a). Fig. 5(b) illustrates the maximum wavelength differences in each channel for the 6 laser arrays, which vary from 0.36 nm to 1.17 nm with a mean value of 0.788 nm (±0.394 nm) and standard deviation of 0.222 nm. It should be noted that the wafer with epitaxy (epi-wafer) is a commercially available product and is briefly described in following part of Methods and the relative distance between two measured arrays may be very large, which would magnify the effects of non-uniformity of the wafer, non-uniformity in the holographic lithography and imperfection in fabrication. As a result, the absolute accuracy is worse than the relative wavelength accuracy. However, the deviation of 0.394 nm in the mean absolute wavelength is sufficiently small that it can be easily compensated by adjusting the operating temperature of the chip, as the thermally induced wavelength shift is about 0.09 nm/°C.


High channel count and high precision channel spacing multi-wavelength laser array for future PICs.

Shi Y, Li S, Chen X, Li L, Li J, Zhang T, Zheng J, Zhang Y, Tang S, Hou L, Marsh JH, Qiu B - Sci Rep (2014)

(a) The lasing wavelengths of 6 laser arrays with wavelength spacing of 0.8 nm. (b) The maximum wavelength differences for the 15 channels of the 6 randomly selected laser arrays. The mean value is 0.788 nm (±0.394 nm) and standard deviation is 0.222 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4260219&req=5

f5: (a) The lasing wavelengths of 6 laser arrays with wavelength spacing of 0.8 nm. (b) The maximum wavelength differences for the 15 channels of the 6 randomly selected laser arrays. The mean value is 0.788 nm (±0.394 nm) and standard deviation is 0.222 nm.
Mentions: Absolute wavelength accuracy is another key parameter that must be evaluated. We randomly selected 6 laser array bars with 15 wavelengths, for which the same wavelength spacing of 0.8 nm was obtained, as shown in Fig. 5(a). Fig. 5(b) illustrates the maximum wavelength differences in each channel for the 6 laser arrays, which vary from 0.36 nm to 1.17 nm with a mean value of 0.788 nm (±0.394 nm) and standard deviation of 0.222 nm. It should be noted that the wafer with epitaxy (epi-wafer) is a commercially available product and is briefly described in following part of Methods and the relative distance between two measured arrays may be very large, which would magnify the effects of non-uniformity of the wafer, non-uniformity in the holographic lithography and imperfection in fabrication. As a result, the absolute accuracy is worse than the relative wavelength accuracy. However, the deviation of 0.394 nm in the mean absolute wavelength is sufficiently small that it can be easily compensated by adjusting the operating temperature of the chip, as the thermally induced wavelength shift is about 0.09 nm/°C.

Bottom Line: In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost.In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch.As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%.

View Article: PubMed Central - PubMed

Affiliation: National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, Microwave-Photonics Technology Laboratory, Nanjing University, Nanjing, 210093, China.

ABSTRACT
Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard μm-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20 nm, corresponding to a tolerance of ±0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%.

No MeSH data available.