In this paper we report our investigations on the frequency stabilization and frequency measurements of 543 nm HeNe laser. It contains following four di€erent works. (1) Using a metal laser tube we have built an iodine-stabilized 543 nm HeNe laser by the Frequency-Modulation (FM) spectroscopy. The signal-to-noise ratio of the hyper®ne spectrum reached 2 ́ 10 at 1 s sampling time. (2) We have bu...

The absolute frequency of the In(+) 5s(2) (1)S(0)5s5p (3)P(0) clock transition at 237 nm was measured with an accuracy of 1.8 parts in 10(13). Using a phase-coherent frequency chain, we compared the (1)S(0)(3)P(0) transition with a methane-stabilized HeNe laser at 3.39 microm, which was calibrated against an atomic cesium fountain clock. A frequency gap of 37 THz at the fourth harmonic of the H...

BACKGROUND In chronic wounds, especially burn scars, malignant tumors can arise. However, it is rare for a subacute burn injury to change to a malignant lesion within one month. Moreover, a case of squamous cell carcinoma arising from HeNe laser therapy after a chemical burn has never been reported. CASE REPORT In this report, we examine a rare case of squamous cell carcinoma arising from HeN...

Materials and Methods. Testing was conducted on single-use and reusable laser fibers in varying sizes – 200μm, 272μm, 365μm, 550μm and 1000μm. Sizes reflect the true core diameter of each fiber. Fixtures for the testing were built for the 200μm, 272μm, 365μm, 550μm fibers simulating the anatomical curvature that the fiber may be subjected to during a procedure (considered the short-term bend ra...

Mid-infrared radiation near 2.8 mum was generated by difference-frequency generation in an 80-mm-long periodically poled Ti:LiNbO(3) channel waveguide by pump radiation near 1.55 mum (tunable external-cavity laser) and a signal radiation of 3.391 mum (HeNe laser). We obtained a normalized conversion efficiency of 105% W(-1) , which is to our knowledge the highest value ever reported.

We demonstrate a simple and versatile method to greatly extend the tuning range of optical frequency shifting devices, such as acousto-optic modulators (AOMs). We use this method to stabilize the frequency of a tunable narrow-band continuous-wave (CW) laser to a transmission maximum of an external Fabry-Perot interferometer (FPI) with a tunable frequency offset. This is achieved through a servo...

A compact optical clock and frequency comb system is presented, based on a 1 GHz octave-spanning Ti:sapphire laser referenced to the F2(2)(P(7),v3) optical transition in methane at 3.39 microm. The reference methane transition is accessed by a stabilized HeNe laser in a compact transportable format. The output from the octave-spanning Ti:sapphire laser is used to generate a mid-IR comb at the r...

The essential optical components include a 5 mW polarized laser (HeNe); single mode, polarization preserving optical fiber with couplers; Wollaston prism, birefringent plate; water immersion 20x microscope objective; electro-optic modulator, and polarization analyzer. The interferometric microscope needs to be compact and stiff, a combination that can be achieved with Microbench components (LIN...