Product focus: Toptica’s innovations

Terahertz generation
Toptica's lasers are used in two of the most important optical techniques for producing terahertz radiation. Its tunable distributed feedback diode laser systems are used to produce continuous terahertz radiation using difference frequency mixing, while femtosecond fiber lasers are used to generate pulsed terahertz radiation.

Difference frequency mixing is achieved on a semiconductor antenna known as a "photomixer", and for efficient terahertz generation, the laser wavelength must be shorter than that corresponding to the semiconductor bandgap (approx. 870 nm). Further, the laser source must be powerful and, since many terahertz absorption lines are tens or hundreds of gigahertz wide, it must have a large mode-hop-free tuning range.

Toptica has three new product packages for CW terahertz experiments, including a basic version consisting of two tunable DFB laser heads, optional fiber coupling or fiber-optic beam combination, low-noise driving electronics and an analog interface for remote control of operating parameters. The other packages have been optimized for use with high powers and to achieve high-precision frequency control.

Meanwhile, Toptica's FemtoFiber laser series can be used to generate pulsed terahertz radiation with an average power level of 200 mW at 775 nm and 500 mW at 1550 nm. The repetition rate of 100 MHz allows for high-speed sampling, while a pulse duration of less than 100 fs generates broadband terahertz radiation with up to 10 THz bandwidth.

Applications that require optical sampling will also benefit from Toptica's new electronics that allow the pulse trains of two FemtoFiber lasers to be synchronized with a stability (jitter) better of 100 fs.

Quantum Optics & Spectroscopy
Quantum optics and spectroscopy require CW laser systems that offer broad tunability and power levels ranging from 100 mW to 2 W. Toptica's new CW laser products address previously unavailable wavelengths in the deep UV with output powers of more than 100 mW. And in the visible and near infrared, semiconductor amplifier laser systems can boost the output from lower power diode lasers up to 2 W.

New for LASER 2007 are the “next-generation” DL 120 RockSolid tunable diode lasers. Its predecessor, the DL 100, has become the workhorse for many quantum optics and spectroscopy groups around the world while the DL 120 has been designed to achieve greater stability, easier alignment, and the ability to make coarse wavelength adjustments without re-optimization. Digital locking electronics have also been designed to allow even inexperienced users to select a point in an absorption spectrum to which the laser will be locked automatically.

Femtosecond supercontinuum lasers
Toptica's lasers now cover the wavelength range from 500 nm to 2100 nm with its FemtoFiber series of ultra fast mode-locked lasers. Femtosecond erbium fiber lasers provide powerful beams at 1550 and 775 nm, infrared supercontinuums (1000-2100 nm), tunable <30 fs pulses in the 1050-1400 nm range, and tunable picosecond pulses in the 520-700 nm range.

Ultrafast ytterbium fiber lasers
Toptica is also releasing a new series of mode-locked ytterbium picosecond fiber lasers, which are designed integration into industrial ultrafast laser instruments. According to Toptica, the new lasers offer uptime and lifetime values that meet the highest industrial standards, which is essential for mode-locked laser technology to be economically viable. The lasers typically operate between 1030 nm and 1070 nm and offer pulse durations ranging from picoseconds to sub-picosecond values.

Diode lasers
Toptica says that its diode and ultrashort pulsed fiber lasers achieve new records in wavelength coverage, power and stability. Its single-diode laser modules iBeam and iPulse achieve 18 mW at 375 nm, an important wavelength for flow cytometry and disc mastering, while a record-breaking 120 mW can be produced at 660 nm. Advanced micro-optical alignment transforms the elliptical diode laser beam into a near-perfect circular beam, resulting in what Toptica claims are"market best" beam quality values.