UNIWAVE now provides a new line of ultrafast triplers for Ti:S lasers. With the addition of the ultrafast fs and ps triplers, UNIWAVE has become one power source for wavelength conversions.

The new family of high efficiency triplers consists of a complete line of fs and ps triplers for both Ti:S amplifier and Ti:S oscillator. They are manufactured by Uniwave Technology Inc. based on the new invention of Time PlateÔ - a new time delay device (patent pending hold by Uniwave Technology Inc.).

The new ultrafast triplers are the most compact and user friendly, while setting the record of the highest efficiency. The steps of the separation and recombination of the fundamental and SHG beams in other ultrafast triplers are no longer needed and the spatial overlap of the two beams are automatically obtained with the Time PlateÔ design. The smooth time delay control adds more value to the triplers for your application.

So far all other fs triplers use a delay line for time compensation. The delay line consists of two beam splitters (or diachronic mirrors), several mirrors, and a translation stage (see Fig. 1). It works in three steps: (1) the separation of two laser beams w and 2w ; (2) the two beams traveling through different path and the time delay between them being adjusted by moving the translation stage; (3) the recombination of the two beams. The drawbacks of delay line are that it is complicated, expensive, large size, and very difficult to align.

The Time PlateÔ is invented to overcome the drawbacks of delay line. A Time Plate (TP) consists of a specially designed birefringence crystal. After the SHG stage, a time delay between the two beams w and 2w , which are polarized perpendicularly to each other, is generated. The time delay is compensated after the two beams travel through the time plate since they have different refractive indices n_o and n_eff. The delay time is tunable by rotating the angle of the time plate around the z-axis to change the effective index n_eff. One degree rotation changes the time delay about 10 fs for a 2 mm thick calcite crystal. In the fs triplers, there is no beam separation and recom-bination and the beams w and 2w keep collinear so the spetial overlap are automatically achieved. The better method for spatial and time overlap makes the fs triplers to be very user friendly and more reliable.

There are two tripler models, TP-1A and TP-1B. The model TP-1A is perfect for Ti:S amplifier. The standard tripler is designed for 1 mJ per pulse energy of kHz Ti:S amplifier systems from Spectra-Physics, Coherent , Clark, and Quantronics. The model for much high pulse energy is also available, please consult our sales engineers. The model TP-1B is designed for mode-locked Ti:S oscillator like Spectra-Physics Tsunami and Coherent Mira. The time plate design makes the TP-1B tripler truly user friendly. The alignment becomes so easy that any one can do it himself.

SHG pulse energy >250 m J

SHG pulse width <180 fsec

THG pulse energy >150 m J

THG pulse width <300 fsec

Input: 1 W, 120 fs, 1 kHz at 800 nm.

The TP-1B tripler is based on the Time Plate design and has high conversion efficiency. This feature means great importance in two ways. First, because of the Time Plate technology, the spatial overlap is automatically guaranteed in our TP-1B tripler. When laser alignment has been changed, TP-1B tripler will give out tripled wavelength immediately after realigning the input laser beam through the center of crystals and the Time Plate. Other triplers might completely lose the output due to the small change of the spatial and temporal (within pulse width ~100 fs, or 30m m in spatial change) overlap between the doubling and fundamental beams in the tripling crystal. You might spend a week time just to find the tripled wavelength back if you had lost it by the change of laser alignment. This is because as you optimize the spatial overlap, you might change the temporal overlap, and vise versa. You will find that easy to use is one of the most important factors to choose a tripler besides the conversion efficiency and price. Secondly, the Time Plate replaces some 6 to 7 piece of dichroic mirrors which the fundamental and 2^nd harmonic of the ultra fast laser pulses have to pass through before getting into the THG crystal. This Time Plate design with less optics proves important for ultra-short pulses (<100fs), because there are less group velocity dispersive (GVD) elements involved. Preliminary test shows that we could get less than 200fs pulse width for third harmonic out (input pulse width is 80fs at 800nm).

To correct for chromatic abberations and pulse broadening introduced by optics, UNIWAVE TP-1B tripler employs special broadband highly reflective dielectric concave mirrors for focusing and collimating ultra-fast laser beams in order to achieve high efficiency while preserving the pulse width characteristics.

The system is provided with two sets of optics optimized for 700nm – 900nm and 800nm to 1000nm operations. There are also two sets of non-linear optical crystals especially optimized for fs and ps laser operations. You will find that because of the Time-Plate design, changing optics and crystals are just as easy as dealing with ns lasers. With our unmatched experience and fabrication capability in non-linear optical crystals, we are able to give the best configurations to different customers’ requirements.

The TP-1B tripler has 10%-20% tripling efficiency with 1W average input power at 800nm, 100 fsec pulses with 76 MHz repetition rate.

The TP-1B tripler has the same kind of mechanical dimension and lay out as the TP-1A tripler. Please consult the Dimensions drawing below for details.

UNIWAVE offers a wide range of crystals and optics to optimize the TP-1 triplers for your application. TP-1A works for Ti:S amplifier and TP-1B works for Ti:S oscillator. Both fsec and psec operations are available at 700-900 nm and/or 800-1000 nm. Please consult an UNIWAVE sales engineer with questions on configuration or system efficiencies.

Dimensions: (All dimensions are in inches, unless otherwise specified)

Custom mechanical designs for specific lasers and systems are always available.