TY - JOUR
T1 - Laser terahertz emission microscope
AU - Murakami, Hironaru
AU - Uchida, Naotsugu
AU - Inoue, Ryotaro
AU - Kim, Sunmi
AU - Kiwa, Toshihiko
AU - Tonouchi, Masayoshi
N1 - Funding Information:
Manuscript received March 13, 2007; revised April 18, 2007. This work was supported in part by the Strategic Information and Communications Research and Development Promotion Fund of Ministry of Internal Affairs and Communications (MIC), in part by the Japan Society for the Promotion of Science (JSPS) under Grant-in-Aid for Scientific Research (A) 16206036, and in part by the Special Coordination Fund for Promoting Science and Technology of the Ministry of Education, Sports, Culture, Science and Technology (MEXT). H. Murakami, N. Uchida, R. Inoue, S. Kim, and M. Tonouchi are with Institute of Laser engineering, Osaka University, Suita, Osaka 565-0871, Japan (e-mail: hiro@ile.osaka-u.ac.jp). T. Kiwa is with Department of Electrical and Electronic Engineering, Okayama University, Okayama 700-8530, Japan.
PY - 2007/8
Y1 - 2007/8
N2 - Developments of laser terahertz (THz) emission microscope (LTEM) systems are reviewed. Femtosecond lasers can excite the THz wave emission from various electronic materials, such as semiconductors, high-temperature superconductors, manganites, multiferroic oxides, etc., due to ultrafast current modulation. Limiting the topic to semiconductors, the current modulation is realized by acceleration or deceleration of photoexcited carriers due to the local electric field extrinsically or intrinsically induced at the laser illumination spot. Thus, LTEM has a potential to visualize the local electric field distribution and photoresponse without any contacts or damages. We have ever constructed prototype free-space type and scanning fiber-probe (SFP) type LTEM systems with transmission or reflection mode. The system performance of the SFP-LTEM has been greatly improved compared with that for the prototype one. The spatial resolution of the SFP-LTEM system has a minimum spatial resolution less than 3 mum , which is defined by the laser beam diameter. The compact SFP-LTEM system, in particular the reflection system, has the potential to be utilized for wide applications as well as various materials. In this review paper, we introduce the details of the LTEM systems and example applications for the evaluation of electric field distribution in integrated circuits and supercurrent distribution in high-temperature superconductors.
AB - Developments of laser terahertz (THz) emission microscope (LTEM) systems are reviewed. Femtosecond lasers can excite the THz wave emission from various electronic materials, such as semiconductors, high-temperature superconductors, manganites, multiferroic oxides, etc., due to ultrafast current modulation. Limiting the topic to semiconductors, the current modulation is realized by acceleration or deceleration of photoexcited carriers due to the local electric field extrinsically or intrinsically induced at the laser illumination spot. Thus, LTEM has a potential to visualize the local electric field distribution and photoresponse without any contacts or damages. We have ever constructed prototype free-space type and scanning fiber-probe (SFP) type LTEM systems with transmission or reflection mode. The system performance of the SFP-LTEM has been greatly improved compared with that for the prototype one. The spatial resolution of the SFP-LTEM system has a minimum spatial resolution less than 3 mum , which is defined by the laser beam diameter. The compact SFP-LTEM system, in particular the reflection system, has the potential to be utilized for wide applications as well as various materials. In this review paper, we introduce the details of the LTEM systems and example applications for the evaluation of electric field distribution in integrated circuits and supercurrent distribution in high-temperature superconductors.
KW - Femtosecond laser
KW - Fiber probe
KW - High-temperature superconductor
KW - Microscope
KW - Terahertz
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U2 - 10.1109/JPROC.2007.898829
DO - 10.1109/JPROC.2007.898829
M3 - Article
AN - SCOPUS:41949122424
SN - 0018-9219
VL - 95
SP - 1646
EP - 1657
JO - Proceedings of the IEEE
JF - Proceedings of the IEEE
IS - 8
M1 - 4337847
ER -