Efficient coherent light generation by hybrid photonic crystal fibers

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K18891
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Electrical and electronic engineering and related fields
• Research Institution: Toyota Technological Institute
• Principal Investigator: Ohishi Yasutake 豊田工業大学, 工学(系)研究科(研究院), 教授 (80360238)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: フォトニック結晶ファイバ / 非線形光学 / 四光波混合 / コヒーレント光 / テルライトガラス / カルコゲナイドガラス

Outline of Final Research Achievements

A step-index tellurite optical fiber with loss 0.02 dB/m at 1545 nm was fabricated. With a nanosecond laser operated at 1545 nm as the pump source, the signal light at 772 nm was observed in the 2.5 m tellurite fiber with a conversion efficiency up to 1.15% for the 20 mW pumping, which, to the best of our knowledge, is the highest for non-silica optical fibers. It can be explained by a χ(3)-induced model via the four-wave-mixing effect, where a signal wave and a millimeter wave are generated simultaneously. The above analysis of experimental results suggested that χ(3)-induced FWM was a possible explanation for the generation of the signal at 772 nm. According to the degenerate FWM-based model, two pump waves at 1545 nm produced at the same time a signal wave and a millimeter wave. Based on the measured λpump and λsignal, we calculated the millimeter wave frequency to be 0.025 THz. This millimeter wave can be regarded as the idler light the χ(3)-induced FWM effect in the fiber.

Free Research Field

フォトニクス

Academic Significance and Societal Importance of the Research Achievements

CO、NOx等の環境ガスの吸収波長は中赤外域にあり、また、神経ガス（タブン、サリン、VX ガス）、びらん剤（マスタードガス、ルイサイト）、爆薬、麻薬等の吸収帯は中赤外からテラヘルツ域に集中する．それらを高速高精度で測定できれば、世界的に課題となっているテロ対策や犯罪対策に大いに役立つ．したがって、光源として全く考えられてこなかったアイドラ光を使った単一素子で中赤外域からテラヘルツ領域の高強度コヒーレント光が発生できれば、これまでにないコヒーレント光源が開発可能となり、環境・医療・新薬創生・セキュリティー対策等の応用に広く展開できるので、本研究成果は、それら分野の革新的発展に寄与できる．