本實驗主要討論溫度對電磁誘發透明的影響。利用階梯式電磁誘發透明，將探測光頻率鎖在銫原子|6S1/2,F=4>→|6P3/2,F′=5>，耦合光以|6P3/2,F′=5>→|8S1/2,F′′=4>為頻率中心來回掃動，將銫原子氣室的溫度控制在10°C至30°C(其不準度為0.005°C)，觀察電磁誘發透明之光譜變化。以optical Bloch equation作為理論模型，並考慮溫度造成光學深度(optical depth)、速度群的分布及去相率(dephasing rate)之影響，並加入re-absorption效應，將實驗數據及理論模型進行擬合，可發現若對於所有速度群原子給予相同的去相率，則去相率會隨著溫度增加而增加，代表溫度增加時，原子均速度變大、密度變高，因此碰撞機率愈大，使得去相率增加。因此我們提出一個去相率與速度相關的函數模型(Γ2→Γ2*e^(a|v|)，Γ3→Γ3*e^(b|v|))，其中溫度尚存在其他複雜因素(例如：原子密度…等)，將這些複雜因素結合在參數a及b中，由模擬結果可得，在b為0.01時，10°C至30°C的a分別為0.075~0.11的定性增加，成功擬合溫度上升時電磁誘發透明窗口兩側的增強吸收訊號會消失的現象。由於本實驗所使用的是10cm長的銫原子氣室，隨著溫度的增加造成原子密度變高，導致在長氣室中產生了電磁誘發透明的re-absorption現象，因此，探測光強度會因為光在介質中的傳遞深度而衰減。在低溫及高溫部分的穿透強度皆有變弱的趨勢，因為在低溫時原子密度較低，對於電磁誘發透明的貢獻較少，但在溫度升高時，須考慮re-absorption的效應，同時會造成原子碰撞劇烈而導致去相率變大，這兩個因素皆會削弱室溫中電磁誘發透明效應，理論的模擬也成功的得到電磁誘發透明率與溫度的關聯。
在V型雙光子電磁誘發透明實驗中，利用Ti:sapphire雷射入射氣室後，再用反射鏡製造兩道同頻率的光，產生雙光子躍遷，其頻率為銫原子|6S1/2,F=4>→|9S1/2,F′′=4>之躍遷頻率的一半，作為耦合雷射，再引入ECDL作為探測雷射，並將其頻率鎖在|6S1/2,F=4>→|6P3/2,F′=5>之躍遷頻率。在此實驗中，改變銫原子氣室的溫度，並偵測電磁誘發透明之穿透譜線，觀察氣室溫度與譜線之關係。欲達到雙光子躍遷，銫原子氣室須加至高溫(約65°C)，但高溫時探測光不易穿透，系統尚在測試中。

Thermal effects on the ladder-type of electromagnetically induced transparency (EIT) in a cesium vapor cell were investigated. The coupling beam for the cascade-type EIT was scanned around the resonance frequency, Cs |6S3/2,F′=5>→|8S1/2,F′′=4>, while the probe beam was locked to the hyperfine transition of Cs |6S1/2,F=4>→|6S3/2,F′=5>. The temperature of cesium vapor cell was stabilized (the uncertainty is about 0.005°C) in the range of 10 to 30°C by using a home-made temperature controller. These thermal effects on the EIT signal were well explained by numerically solving the optical Bloch equation (OBE). In this simulation, the thermal velocities averaging, dephasing rate due to atomic collisions, the atomic density, and the effect of re-absorption have to take into account.
If the dephasing rate is independent of atomic velocities, experimental data show that the dephasing rate is increasing while increase the cell temperature, i.e., the atomic average velocity and the density are higher at higher temperature. Therefore, the collision rate is increasing and hence dephasing rate is increasing too. In this study, a model of velocity dependent dephasing rate, (Γ2→Γ2*e^(a|v|),Γ3→Γ3*e^(b|v|)), where Γ is the decay rate, a and b are constant, and v is the velocity of atoms, was proposed to solve the OBE to fit the experimental spectra. At cell temperature from 10℃ to 30℃, b is fixed at 0.01 and a is increasing from 0.075 to 0.11 by fitting the observation spectra. This model is also successfully predicting that the enhanced absorption wings on the EIT spectrum at higher temperature will be fading out.
The transmittance of the EIT signal is decreasing dramatically at higher temperature. For higher temperature, although the larger atom number in the EIT interaction regime is favor to the transmittance of the EIT, however, the higher density will cause a larger dephasing rate and the re-absorption effect become severe and hence lower the transmittance rate. The transmittance rate is decreasing at lower temperature due to the fewer atom number participating the interactions.
For V-type two-photon EIT, the experimental system has been setup for testing. The cell temperature was raised to 65℃ in order to increase the probabilities of two-photon transitions. However, the transmittance of the probe laser becomes too weak to be detected. The experimental conditions are still under investigation.

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