應用一矽彈簧片於外腔雷射系統在原子物理領域的應用

Development of an extended cavity laser system by using a silicon flexure for applications in atomic physics

黃國淵(Kuo-Yuan Huang)

指導教授 ： 莊賀喬

國立臺北科技大學/機電學院/機電整合研究所/碩士(2011年)

https://doi.org/10.6841/NTUT.2011.00358

摘要

外腔式半導體雷射(External Cavity Diode Laser, ECDL)系統具有體積小、構造簡單穩定、幾乎是隨開即用、不須時常調校、高能源效率、以及維護費用低廉等優點。這種雷射系統已被廣泛應用於原子物理實驗中，例如雷射冷卻、原子氣體之玻色-愛因斯坦凝聚等[1-2]。目前外腔雷射大部分皆為Littrow或是Littman的結構[3-4]。然而，此類系統之光柵轉動機制需要特別講究始能達到大範圍無跳模掃頻，且光柵機構重量大造成掃頻速率遲緩。此外Littrow結構雷射，掃頻時將造成雷射束方向改變。而在原子物理系統的應用推廣上，例如”縮小及可攜式玻色-愛因斯坦凝聚系統”，此類型雷射系統的體積仍嫌龐大。藉由微機電製程的發展，本論文中使用了矽彈簧元件與體積全像光柵(VHG)製造穿透式光柵之外腔雷射系統，縮小了雷射系統的體積與重量(體積為26.3×20×20 mm3)。使用穿透式光柵，在掃頻時亦不會改變雷射出射方向。同時本系統藉由矽彈簧元件取代了一般撓性元件，可進一步提升其雷射系統本身的剛性以及提高雷射穩定性為目標。

關鍵字

外腔雷射 ； 雷射冷卻 ； 玻色-愛因斯坦凝聚 ； Littrow ； Littman ； 體積全像光柵(VHG)

並列摘要

External Cavity Diode Laser (ECDL) systems are compact, simple structured with high stability, almost turn-key operation, high energy efficiency, and low maintenance cost. This kind of systems has been widely used in atomic physics experiments, such as laser cooling and atomic Bose - Einstein condensation [1-2]. Most ECDL’s are in either Littrow or Littman configurations [3-4]. Frequency tuning on those types of ECDL’s is achieved by tuning the grating angle, which requires special attention to achieve a wide mode-hop-free frequency tuning range. The weight of grating also limits its frequency response to an external modulation and thus the sweep speed of the laser frequency. In this study, a unique design of a micromachined silicon flexure combined with a Volume Holographic Grating (VHG) has been utilized to construct a compact ECDL. The size of this ECDL is 26.3×20×20 mm3, only of a fraction of a typical Littrow ECDL. The silicon flexure is used to replace traditional metal flexures for grating angle tuning. Our compact laser design combined with silicon flexure should enhance the rigidity and stability of the laser cavity.

並列關鍵字

External Cavity Diode Laser ； Bose-Einstein condensations(BEC) ； Littrow ； Littman ； Volume Holographic Grating (VHG)

參考文獻

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