Q-Peak, through its active Research business, is always advancing the state-of-the-art in solid state and nonlinear optics technologies. When these advances reach an appropriate level, they can be offered as firm-priced products, rather than as part of research contracts. Below, we show some technologies that have advanced to the level of new products.
Q-Peak has developed a laser head mechanical design for a Gain Module oscillator that provides an unusually high degree of power stability. The design is based on a box-structure optical chassis. Shown below is the head (drawing with cover off on left, picture with cover on right), along with a graph below of amplitude stability over a period of 100 hours, showing that the power level varied no more than 0.04 W (RMS) about and average level of 20.06 W.
The Gain Module technology operates effectively in both oscillator and amplifier configurations. For some applications, a pulse or spectral format different from that provided by a Gain Module oscillator may be needed. A variety of examples can be found in the Technical Papers section of this site, resulting from our Research efforts, including devices based on microchip (sub-ns) and mode-locked (5-100 ps) oscillators. We show below one example of a device that has transitioned to product status. Our Short-Pulse Oscillator employs an end-pumped, low-power, Q-switched Nd:YLF laser, with a short optical cavity and miniature Q-switch that allows generation of short pulses at very high pulse rates. Shown below is a picture of the Short-Pulse Oscillator laser head (left) and a graph (right) of pulsewidth and pulse energy as a function of pulse rate. Combined with a four-stage MPS amplifier chain, the Short-Pulse Oscillator provides average powers exceeding 85 W at 1047 nm, and high powers at the second, third and fourth harmonics. More details can be found here: Short-pulse, high-repetition rate, high-power Nd:YLF MOPA system
Q-Peak is now developing higher-power Gain Modules, capable of producing about twice the power of our standard Gain Module. An example of a prototype laser head employing a High-Power Gain Module appears below, with dimensions in mm. The head, based on the same technology employed for the high-stability Gain Module oscillator, above, consists of a standard Gain Module oscillator and High-power Gain Module amplifier, along with a second-harmonic generator. The device generates an average power exceeding 35 W at the second harmonic.
One developing category of solid state laser technology, the hybrid laser, combines the best properties of fiber lasers, the ability to produce efficient, high-beam-quality cw power, with those of bulk-crystal lasers, the ability to store energy and generate high peak powers in the Q-switched mode of operation. Q-Peak has developed one such system, the Tm:fiber-pumped Ho:YLF laser, and set record peak- and average-power levels at 2050 nm from a master-oscillator, power amplifier (MOPA), as part of a research program to develop sources used for laser-ultrasonics testing of materials. For an application in ladar, we designed and built an oscillator-only Q-switched Ho:YLF laser that generated 10 mJ-energy 16-ns-duration, linearly polarized, TEM00 pulses at pulse rates of 500 Hz. Appearing below is an exploded-view drawing of the air-cooled laser head for the system, with the cooling unit on the lower level and the Ho:YLF laser on the upper level. Also below is a photograph of the assembled laser head.
The Ti:sapphire laser, which Q-Peak helped to transition to commercial status (see Product History) requires an ion or solid state laser as a pump source. Ultrafast lasers based on rare-earth Yb-doped laser materials, while not being able to produce as short a pulse as the Ti:sapphire laser, can operate in the 1050-nm wavelength region with pumping from compact, efficient, and relatively low-cost diode lasers. Q-Peak is actively pursuing development of Yb-doped ultrafast lasers, and as part of a research effort has developed not only an oscillator but also a chirped-pulse amplifier to generate nearly 3 GW-peak-power pulses at a 250-Hz rate. The system schematic is show below.
The system was packaged for field applications, with the laser head, shown in two drawings below sized at 66 x 21.5 x 40 cm. The small size was made possible, in part, by the use of chirped voulme Bragg gratings to both stretch and compress the pulses
Another example of a diode-pumped ultrafast system is shown in the schematic below. We used an extended optical cavity to build a 10-MHz pulse-rate Yb:CaF2 laser, which generated 1 W of average power with 320-fs-pulses, for a peak power exceeding 300 kW/pulse at 1050 nm. We converted 50% of the power to the second harmonic, for application to materials processing.
We expect products to emerge from this technology in the near future.