Passively Q-Switched Er-Doped Fiber Lasers Using Alcohol

A passively Q-switched Er-doped fiber laser using a simple and cost-effective saturable absorber (SA) of alcohol has been demonstrated. The SA is made through filling anhydrous alcohol in the gap between the end-facets of two optical patch cords, which are inserted into a cannula. The modulation depth of the SA with 820-μm alcohol layer is measured to be 18%. Based on such an SA, the Q-switching operation in the Er-doped fiber laser has been achieved. The average output power of the Q-switched fiber laser is 30.3 mW with the pulse repetition rate of 81.9 kHz, and thus, the pulse energy is up to 348.6 nJ. To the best of our knowledge, it is the first demonstration of the passively Q-switched laser based on an alcohol SA. This provides the further evidences indicating the possibility of organic liquid as effective SAs for pulsed lasers.