An improved device and method for safe, accurate and efficient surgical procedures are disclosed. The disclosed device is an optical fiber set with an asymmetric distal end configuration, comprising a bent tip fiber with a fused sleeve as an integral part of it, placed at the fibers distal (output) end and with a rotatable connector at the proximal (input) side. Fiber tip and tissue-contacting surface located at the distal end of the tip may be constructed with different shape configurations, such as convex tip to improve focusing characteristics, concave tip to achieve diverging irradiation or an expanded beam tip to achieve an effect similar to that obtained by electrosurgical tools. A grip guarantees and enhances the ability to twist and rotate it easily. In another preferred embodiment, twisting maneuvers are enhanced through a special configuration. Both special features (bent tip and rotatable connector), allow for improved and enhanced treatment of diverse pathologies, making possible to efficiently and easily reach and treat specific tissues. Optical fibers steerability, twistability and rotation lead to a more precise and improved effect on tissues. Due to this, easier, faster and more precise and efficient treatments can be performed by its means. For instance, it may be inserted into a cystoscope to perform high power ablation of prostatic tissue for BPH treatments, or steered into one of the prostatic lobes, which can be excavated from the inside in order to relieve pressure on the urethra while maintaining the urethras integrity. Other uses might be the removal of tumorous, hyperplasic or other unwanted tissue in the body. Optical fiber set disclosed can be used with laser sources of various wavelengths, including dual laser sources, but also higher power LED devices or very bright light sources can be used to generate the radiation to be transmitted as well. Due to this novel design, described fiber is easy to put in place, also easy to maintain in con
