Conclusion and Future Work
6.2 Future work
According to the study of VCSEL in this thesis, there are several works for our group to continue and improve the optical and electrical characteristics. One is the heat dissipation problem due to worse thermal conductivity of p-type GaN and sapphire substrate. If we package the laser devices into TO cans or bond them on heat dissipation substrates, we can avoid large thermal effect to destroy the laser devices. Another one is to get better optical confinement according to large refractive index different. The other one is used better current confined layer to decrease the current density that laser devices use. To solve these problems, we have design the new VCSELs structure shown in Figure 6. 1 and Figure 6. 2. In Figure 6. 1, these isolation layers of lower refractive index, such as the implantation area and the AlN layer, can efficiently upgrade both in the current and optical confinement. Figure 6. 2(a) and (b) show the device OM image and the schematic diagram of VCSEL with double dielectric mirrors.
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Figure 6. 1 Electrical pumped of GaN-based VCSEL with optical and current confined layer
Figure 6. 2 (a) The image for EL GaN-based VCSELs with double dielectric mirrors; (b) the schematic diagram of EL GaN-based VCSELs with double dielectric mirrors.
About PCSEL, We will further improve the fabrication techniques of GaN PCSEL to achieve the better laser operation whether in optical pumped and electrically pumped as shown in Figure 6. 3. In Figure 6. 3(a), the research of GaN-based defect mode PhC
131
laser becomes a hot topic according to its specific advantages compared with band-edge mode PhC laser. Therefore, we will also investigate the characteristics of GaN-based defect mode PhC laser. Besides, in order to improve the PhC characteristics, we will further fabricate photonic crystal nanostructure on a thin-GaN bonding structure due to the better epitaxial quality and easy to fabricate electrical devices as shown in Figure 6. 4.
According to these advantages, we expect these structures can finally reduce the threshold condition for both of VCSEL and PCSEL devices.
(a) (b)
Sapphire
Low refractive index layer p-GaN
n-GaN PC region
defect
InGaN/GaN MQW
Figure 6. 3 (a) GaN-based photonic crystal defect laser; (b) electrically pumped GaN-based photonic crystal band-edge laser
Bonding metal Low refractive index layer n-GaN
p-GaN
InGaN/GaN MQW PC region
Substrate
Figure 6. 4 The schematic diagram of thin-GaN PCSEL devices
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Kuo, and S. C. Wang, ”Continuous wave operation of current injected GaN vertical cavity surface emitting lasers at room temperature”, accepted by Appl. Phys. Lett, (2010)
S. W. Chen
3.
, T. C. Lu, Y. J. Hou, T. C. Liu, H. C. Kuo, and S. C. Wang, “Lasing characteristics at different band edges in GaN photonic crystal surface emitting lasers”, Appl. Phys. Lett. 96, 071108 (2010)
S. W. Chen
4. T. C. Lu, J. R. Chen,
, T. C. Lu, and T. T. Kao, “Study of GaN-based photonic crystal surface-emitting lasers (PCSELs) with AlN/GaN distributed Bragg reflectors”, IEEE J. Selected Topics in Qua. Elec., 15, 885 (2009)
S. W. Chen
5.
, H. C. Kuo, C. C. Kuo, C. C. Lee, and S. C. Wang,
“Development of GaN-Based vertical-cavity surface-emitting lasers”, IEEE J.
Selected Topics in Qua. Elec., 15, 850 (2009) S. W. Chen
6. Z. Y. Li, M. H. Lo, C. T. Hung,
, T. T. Kao, C. C. Kao, J. T. Chu, L. F. Lin, H. W. H., T. C. Lu, H. C. Kuo, and S. C. Wang, “Effects of inhomogeneous gain and loss on nitride-based vertical-cavity surface emitting lasers”, Jpn. J. Appl. Phys., 48, 04C127 (2009)
S. W. Chen
7. T. C Lu,
, T. C. Lu, H. C. Kuo, and S. C. Wang,
“High quality ultraviolet AlGaN/GaN multiple quantum wells with atomic layer deposition grown AlGaN barriers”, Appl. Phys. Lett, 93, 131116 (2008)
S. W. Chen,
8. T. C. Lu,
T. T. Kao, T. W. Liu, “Characteristics of GaN-based photonic crystal surface-emitting lasers”, Appl. Phys. Lett, 93, 111111 (2008)
S. W. Chen
9. T. C. Lu, J. T. Chu,
, L. F. Lin, T. T. Kao, C. C. Kao, P. Yu, H. C. Kuo, and S. C.
Wang, “GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector”, Appl. Phys. Lett, 92, 011129 (2008)
S. W. Chen
10. S. C. Wang, T. C. Lu, C. C. Kao, J. T. Chu, G. S. Huang, H. C. Kuo,
, B. S. Cheng, H. C. Kuo, and S. C. Wang, “Lasing behavior, gain property, and strong coupling effects in GaN-based vertical-cavity surface emitting lasers”, Jpn. J. Appl. Phys. 47, 6655 (2008)
S. W. Chen, T.
T. Kao, J. R. Chen, and L. F. Lin, “Optically pumped GaN-based vertical cavity
133
surface emitting lasers: technology and characteristics”, Jpn. J. Appl. Phys. 46, 5397 (2007)
11. J. S. Hwang, Z. S. Hu, T. Y. Lu, L. W. Chen, S. W. Chen, T. Y. Lin, C. L. Hsiao, K.
H. Chen, and L. C. Chen, “Photo-assisted local oxidation of GaN using an atomic force microscope”, Nanotechnology, 17, 3299 (2006)
International Conference:
1. T. C. Lu, S. W. Chen
2.
, T. T. Wu, C. K. Chen, C. H. Chen, P. M. Tu, Z. Y. Li, H. C.
Kuo, and S. C. Wang, "CW current injection of GaN-based vertical cavity surface emitting laser with hybrid mirrors at room temperature". ISLC 2010
S. W. Chen
3. T. C. Lu,
, T. C. Lu, Y. J. Hou, T. C. Liu, H. C. Kuo, and S. C. Wang,
"Angular-resolved lasing characteristics at different band edges in GaN photonic crystal surface emitting lasers", CLEO 2010
S. W. Chen
4.
, T. T. Kao, T. C. Liu, C. K. Chen, Y. J. Hou, C. H. Chen, P. S.
Weng, Z. Y. Li, H. C. Kuo, and S. C. Wang, "GaN-based two dimensional photonic crystal surface-emitting lasers with AlN/GaN DBR", OPTO/SPIE 2010
S. W. Chen
5.
, T. C. Lu, T. T. Kao, Y. J. Hou, T. C. Liu, P. S. Weng, Z. Y. Li, H. C. Kuo, and S. C. Wang, "The lasing characteristic of GaN-based photonic crystal surface-emitting lasers", MOC 2009
S. W. Chen
6.
, T. T. Kao, Y. J. Hou, P. S. Weng, T. C. Liu, T. W. Liu, T. C. Lu, H. C.
Kuo, and S. C. Wang, "Coupled wave model for GaN-based 2-D photonic crystal surface-emitting lasers", SSDM 2009
S. W. Chen
7. J. S. Hwang, K. Y. Chen, W. S. Syu,
, C. K. Chen, T. T. Kao, C. H. Chen, M. H. Lo, Z. Y. Li, T. C. Lu, H. C.
Kuo, and S. C. Wang, "Fabrication of high qualify factor of GaN-based vertical-cavity light emitting diodes with AlN/GaN and Ta2O5/SiO2 hybrid mirrors", SSDM 2009
S. W. Chen
8.
, S. J. Hong, H. P.Chiang, S.
Chattopadhyay, K. H. Chen, and L. C. Chen, "Silver nano-crystal decorated silica nanowires on quartz as versatile surface-enhanced Raman scattering substrate", CLEO/PR 2009
S. W. Chen, T. T. Kao, T. C. Lu, H. C. Kuo, S. C. Wang, "Progress of GaN-based
134
vertical cavity surface emitting lasers", APWS 2009.
9. S. C. Wang, T. C. Lu, H. C. Kuo, S. W. Chen
10. T. C. Lu, T. T. Kao,
, T. T. Kao, "GaN-based vertical cavity surface emitting laser and photonic crystal surface emitting laser", ACP 2009.
S. W. Chen
11.
, J. R. Chen, C. C. Kao, H. C. Kuo, and S. C. Wang,
"Continuous-wave operation of GaN-based vertical cavity surface emitting lasers by current injection", CLEO 2009.
S. W. Chen
12. H. C. Kuo, T. C. Lu,
, T. T. Kao, T. W. Liu, T. C. Lu, H. C. Kuo, and S. C. Wang, "Lasing characteristics of GaN-based photonic crystal surface-emitting lasers", PR/CLEO 2009.
S. W. Chen
13.
, T. T. Kao, Z. Y. Li, and S. C. Wang, “Current injection of GaN-based vertical-cavity surface-emitting lasers at 77K", PR/CLEO 2009.
S. W. Chen
14.
, C. H. Chiu. T. T. Kao, L. F. Lin, T. C. Lu, H. C. Kuo,S. C. Wang, "Light output enhancement of GaN-based photonic crystal LED with AlN/GaN DBR", SSDM 2008.
S. W. Chen
15.
, T. T. Kao, C. C. Kao, J. T. Chu, L. F. Lin, H. W. Huang, T. C. Lu, H. C.
Kuo, S. C. Wang, "Effects of inhomogeneous gain and loss on nitride-based vertical cavity surface emitting lasers", SSDM 2008.
S. W. Chen
16. T. C. Lu,
, T. T. Kao, T. C. Lu , C. C. Kao, L. F. Lin, T. W. Liu, H. C. Kuo, and S.
C. Wang," The lasing action of GaN-based two dimensional surface-emitting photonic crystal laser", APOC/SPIE 2008.
S. W. Chen
17. H. C. Kuo,
, T. T. Kao, C. C. Kao, L. F. Lin, T. W. Liu, H. C. Kuo, and S. C.
Wang, "Performance of GaN-based surface-emitting photonic crystal Laser", IWN 2008.
S. W. Chen
18. T. C. Lu, T. T. Kao,
, T. T. Kao, C. C. Kao, J. R. Chen, T. C. Lu, and S. C. Wang,
"Blue GaN-based vertical cavity surface emitting lasers by CW current injection at 77K", OPTO/SPIE 2008.
S. W. Chen
19. T. C. Lu, T. T. Kao,
, C. C. Kao, H. C. Kuo, S. C, Wang, "Fabrication and performance of GaN-based two dimensional photonic crystal surface emitting lasers", ISLC/LEOS 2008.
S. W. Chen, T. W. Liu, P. Yu, H. C. Kuo, S. C. Wang,
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"GaN-based two dimensional photonic crystal surface emitting lasers", CLEO 2008.
20. M. H. Lo, S. W. Chen
21. T. C. Lu, T. T. Kao,
, Z. Y. Li. T. C. Lu, H. C. Kuo and S. C. Wang, "AlGaN/GaN multiple quantum wells grown by atomic layer deposition Lasers", CLEO 2008.
S. W. Chen
22. M. H. Lo,
, C. C. Kao, H. C. Kuo, S. C. Wang, "CW lasing of current injection blue GaN-based vertical cavity surface emitting lasers", CLEO 2008.
S. W. Chen, T. C. Lu, H. C. Kuo, S. C. Wang, "Atomic layer deposition of AlGaN/GaN multiple quantum wells by MOCVD", MRS 2008.
Domestic Journal:
1. S. W. Chen
2.
, B. S. Cheng, T. C. Lu, H. C. Kuo, “Characteristics of GaN-based photonic crystal light emitting diodes and surface-emitting lasers”, 第102期光學工 程學會季刊
S. W. Chen, C. K. Chen, T. C. Liu, C. H. Chen, P. S. Weng, Y. J. Hou, T. T. Kao, T. C.
Lu, H. C. Kuo, and S. C. Wang, “The development of GaN-based vertical-cavity surface emitting laser”, 2009台灣雷射科技應用協會季刊(VOL.6)
Domestic Conference:
1. S. W. Chen
2. C. W. Guo,
, G. L. Ku, C. H. Chen, Y. J. Wu, J. S. Hwang, "Broadband anti-reflection of aligned silicon nanowires", Proceedings of Optics and Photonics Taiwan 2006.
S. W. Chen
3.
, L. W. Chen, J. S. Hwang, "Growth and application of Germanium Oxide, Silicon Oxide, and Zinc Oxide nanowires", Proceedings of Optics and Photonics Taiwan 2005.
S. W. Chen
4.
, G. L. Ku, C. H. Chen, Y. J. Wu, J. S. Hwang, "Broadband anti-reflection of aligned silicon nanowires", Annual Meeting of the Physical Society of the Republic of China 2006.
S. W. Chen
5. C. W. Guo, Z. Y. You,
, Y. J. Wu, J. S. Hwang, "Broadband anti-reflection of aligned silicon nanowires prepared by electroless metal deposition with etching", Taiwan Nano Tech 2006.
S. W. Chen, J. S. Hwang, J. H. Lin, T. H. Huang, J. P. Chu, "A simple method for growth of large quantity silica nano-wires", Annual Meeting of the
136
Physical Society of the Republic of China 2005.
6. S. W. Chen
7.
, C. C. Kao, K. F. Yeh, J. T. Chu, W. L. Peng, H. W. Huang, T. C. Lu, H. C.
Kuo and S. C. Wang, "Characteristics of nano-roughened GaN light-emitting diodes formed by ICP dry etching and laser lift-off technique", Proceedings of Optics and Photonics Taiwan 2007.
S. W. Chen
8. M. H. Lo,
, J. S. Hwang, S. H. Hsu, Y. J. Cheng, M. H. Lo, C. H. Chiu, H. C. Kuo, T.
C. Lu, S. C. Wang, C. C. Kao, L. F. Lin, "Optical characteristic of aligned silicon nanowires", Proceedings of Optics and Photonics Taiwan 2007.
S. W. Chen
9. S. C. Wang, T. C. Lu, H. C. Kuo,
, T. C. Lu, H. C. Kuo and S. C. Wang, "Atomic layer deposition of AlGaN/GaN multiple quantum wells by MOCVD", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
10. T. C. Liu,
, and Tsung-Ting Kao, "CW lasing of current injection blue GaN-based vertical cavity surface emitting laser", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
11.
, T. T. Kao, T. W. Liu, T. C. Lu, H. C. Kuo, and S. C. Wang,
"Coupled-wave model for GaN-based 2-D photonic crystal surface-emitting lasers", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
12. C. K. Chen,
, T. W. Liu, T. C. Liu, C. K. Chen, Z. Y. Li ,T. C. Lu, H. C. Kuo, and S. C.
Wang, "GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
13.
, T. C. Liu, L. F. Lin, T. C. Lu, Z. Y. Li ,H. C. Kuo, S. C.
Wang, "Light output enhancement of GaN-based photonic crystal LED with AlN/GaN DBR", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
14. M. C. Liu, T. C. Lu, J. T. Chu,
, M. H. Lo, T. T. Kao, C. C. Kao, J. T. Chu., L. F. Lin, H. W. Huang, T. C.
Lu, H. C. Kuo, S. C. Wang, C. C. Kuo, and C. C. Lee, "Effects of inhomogeneous gain and loss on nitride-based vertical-cavity surface emitting Lasers", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen, B. S. Cheng, H. C. Kuo, S. C. Wang,
"Temperature dependent gain characteristics in GaN-Based vertical-cavity surface-emitting lasers with InGaN multiple quantum wells", Proceedings of Optics
137
and Photonics Taiwan 2008.
15. J. S. Hwang, K. Y. Chen, W. S. Syu, S. W. Chen
16. B. S. Cheng, J. T. Chu,
, S. J. Hong, H. P. Chiang, S.
Chattopadhyay, K. H. Chen, L. C. Chen, "Preparation of silver nano-crystal decorated silica nanowires on quartz as versatile surface-enhanced Raman scattering substrates enabling wide range measurement", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
17.
, T. C. Lu, H. C. Kuo, S. C. Wang, "Lasing behavior and analysis in GaN-based vertical-cavity surface-emitting lasers", Proceedings of Optics and Photonics Taiwan 2008.
S. W. Chen
18. H. C. Kuo,
, T. C. Lu, L. F Lin, T. T. Kao, C. C. Kao, P. Yu, H. C. Kuo, and S. C.
Wang, "GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector", Symposium on Nano Device Technology 2008.
S. W. Chen
19.
, T. T. Kao, C. C. Kao, C. H. Chiu, T. C. Liu, M. C. Liu, C. C.
Ke, Y. N. He, T. C. Lu, and S. C. Wang, "CW current injection of blue GaN-based vertical cavity surface emitting lasers at 77K", 第 26 屆光譜研討會
S. W. Chen
20.
, T. T. Kao, L. F. Lin, T. C. Lu, C. C. Kao, P. Yu, H. C. Kuo, and S. C.
Wang, "GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector", Annual Meeting of the Physical Society of the Republic of China 2009.
S. W. Chen
21. Y. J. Hou,
, T. T. Kao, T. W. Liu, K. W. Hsu, T. C. Lu, H. C. Kuo, and S. C. Wang,
"Characteristic of GaN-based photonic crystal surface-emitting lasers", Annual Meeting of the Physical Society of the Republic of China 2009.
S. W. Chen
22. C. H. Chen,
, T. C. Liu, P. S. Weng, C. H. Chen, C. K. Chen, T. T. Kao, T.
C. Lu, H. C. Kuo, Shing-Chung Wang, "The angled resolved study of GaN-based 2-D photonic crystal surface emitting lasers", Proceedings of Optics and Photonics Taiwan 2009.
S. W. Chen, C. K. Chen, P. S. Weng, Y. J. Hou, T. T. Kao, T. C. Lu, H.
C. Kuo, and S.C. Wang, "Study of GaN-based VCSELs with different ITO layer structure", Proceedings of Optics and Photonics Taiwan 2009.
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Patent:
1. 陳士偉
2. 鄭柏孝，
，盧廷昌，郭浩中，王興宗 “利用反射鏡及低折射率層製作光子晶體雷
射” (台灣、美國、日本專利申請中）
陳士偉，邱清華，盧廷昌，郭浩中，王興宗“製作包含透明導電玻璃 及無裂縫的氮化鋁/氮化鎵系列反射鏡之可電激發面射型雷射”(台灣、美國、
日本專利申請中）