Terahertz quantum cascade lasers based on (GaN)m/(AlN)n monolayer superlattices in order to exploit their potential for high temperature operation

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K14113
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Crystal engineering
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Wang Ke 国立研究開発法人理化学研究所, 光量子工学研究センター, 研究員 (60532223)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: Quantum cascade laser / MBE / GaN

Outline of Final Research Achievements

The GaN THz QCL waveguides are carefully investigated. The possible methods have been developed to fabricate low loss and high confinement waveguide for both single-metal-surface-plasmon and double-metal designs. Epitaxial growth technology for GaN/AlGaN THz QCL structures have been developed by using both MBE and MOCVD methods. High quality QCL structures have been achieved.
A Non-Equilibrium Green’s Function (NEGF) method has been used to analyse the carrier transport and gain properties of GaN/AlGaN THz QCL structures. The gain is calculated in a self-consistent way accounting for the correlation effects in the broadening of different levels. The simulation results demonstrate that the gain spectra can be narrow enough and the peak gain can be high enough for lasing at 7 THz at 280 K for a preliminary design.

Free Research Field

III nitride semiconductor physics and devices

Academic Significance and Societal Importance of the Research Achievements

テラヘルツ量子カスケードレーザ(THz-QCL)は小型、高出力、狭線幅、安価、連続動作可ななテラヘルツレーザ光源として今後の実用化が期待されている。既にテラヘルツパラメトリック発振器などを用いて実用化しているテラヘルツ分析装置、各種透視・非破壊検査用の光源の置き換え、また、携帯用の検査用レーザ光源としての応用が期待されている。テラヘルツ光源の応用範囲は、郵便物や税関検査などのセキュリティ検査、食品などの異物混入検査、ICチップ検査などの電子産業への応用、火傷診断、癌細胞の識別、虫歯の検査などの医療応用、農作物検査、構造物内部の検査など、非常に広範囲にわたる。