Biomedical subjects

Marc Eichhorn

Publications and source records attributed to Marc Eichhorn.

3 recordsLinked to original sources

PubMed2005

High-peak-power Tm-doped double-clad fluoride fiber amplifier.

A diode-pumped Tm-doped double-clad fiber-optic amplifier is reported that provides up to 5 kW of peak power at pulse durations of 30 ns and a repetition rate of 33.5 kHz. When the repetition rate is increased to 123.6 kHz, the peak power drops to 1.5 kW, while the average output power of the amplifier stays at 6.5 W with a slope efficiency of 34.9%. As an amplifier the fiber can be saturated by a very low average launched input power of only 36 mW at 1.87 microm and yields the same average output power as in a fiber laser or amplified spontaneous emission source setup for all the repetition rates investigated. The peak powers reported are to the author's knowledge the highest generated by Tm-doped fiber lasers or amplifiers at repetition rates above 1 kHz with simultaneously short pulse durations of 30 ns.

Journal Article↗

PubMed2005

High-gain Tm-doped fluoride fiber amplifier.

A diode-pumped Tm-doped fiber-optic amplifier that has a small-signal gain of >30 dB at 1870 nm is reported. Output pulses of up to 3-W peak power at a 1-60-kHz repetition rate can be generated by amplification of 20-40-ns laser diode pulses of up to 2-mW launched peak power. The output signal quality, i.e., the ratio of the output pulse energy and the total amplified spontaneous emission (ASE) output energy between two pulses, depends on the relative propagation direction of pump and signal and can be dramatically increased by choice of the correct propagation scheme. In the optimum pump geometry the pulse energy can be raised to as much as 20 times the ASE energy. This is the first report to the author's knowledge of fiber-optic amplification of short diode laser pulses near 1.9 microm with high repetition rates in Tm-doped fibers.

Journal Article↗

PubMed2004

Optical dipole trap inside a laser resonator.

We report the first realization, to our knowledge, of an optical dipole trap inside the active resonator of a laser. The concept, which is demonstrated with a CO2 laser (lambda = 10.6 microm), combines the advantages of optical power enhancement (up to 1.3-kW peak power) with the intrinsic stability of laser intensity as a result of the feedback of the active laser medium. Two kinds of trapping geometries are presented: a Gaussian trap in a transverse TEM00 mode and a boxlike transverse confinement in a superposition of transverse modes. In addition, longitudinal superlattices are created by two-frequency operation of the laser. Transfer efficiencies of up to 50% from a cesium magneto-optical trap are achieved. Storage times (7 = 0.3 s) are mainly limited by the background gas pressure. Possible sources of additional loss of atoms are discussed.

Journal Article↗