Non-collinear Optical Parametric Oscillator Research Articles

Rapidly tunable femtosecond near-UV pulses from a non-collinear optical parametric oscillator.

Broadband tunable femtosecond laser pulses are of great interest in numerous fields, such as spectroscopy or imaging. Here, we report on the generation of rapidly tunable radiation in the near UV by using intracavity non-collinear sum-frequency mixing between the visible pulses of a non-collinear optical parametric oscillator (NOPO) and a near-infrared beam. The NOPO is pumped by the third harmonic of an Yb-based master oscillator fiber amplifier (MOFA). For sum-frequency mixing, remaining fundamental pulses at 1030 nm are used. With this approach, near-UV pulses in a range of 333-413 nm with average output powers up to 90 mW and pulse durations from 158-240 fs are achieved. Fast tunability is demonstrated over the whole tuning range by varying just the cavity length. The system also allows for the generation of two simultaneous synchronized output pulse trains in the visible and the near-UV spectral range.

Real-time stimulated Raman spectroscopy with a non-collinear optical parametric oscillator.

Ultrafast detection of microplastic particles is becoming a vital problem, as these particles are found in water sources worldwide. Ideally, a live analysis in flow is desirable to directly monitor the water quality for contaminations. Therefore, coherent Raman spectroscopy techniques require fast and broadband tunable lasers to address all relevant spectral regions of the investigated samples. In our work, we combine a high power non-collinear optical parametric oscillator with a real-time stimulated Raman scattering spectroscopy setup. The light source is continously tunable from 700 nm to 1030 nm in less than 10 ms, delivering an average output power of more than 500 mW with sub-ps pulses. We show the immediate observation of mixing processes and the detection of microplastic particles in water solution with a spectral window of more than 2000 cm-1.

Widely tunable, high-power, femtosecond noncollinear optical parametric oscillator in the visible spectral range

Ultrafast visible radiation is of great importance for many applications ranging from spectroscopy to metrology. Because some regions in the visible range are not covered by laser gain media, optical parametric oscillators offer an added value. Besides a high-power broadband laser source, the ability to rapidly tune the frequency of pulses with high-power spectral density offers an extra benefit for experiments such as multicolor spectroscopy or imaging. Here, we demonstrate a broadband, high-power, rapidly tunable femtosecond noncollinear optical parametric oscillator with a signal tuning range of 440–720 nm in the visible range. The oscillator is pumped by the third harmonic of an Yb-fiber laser at 345 nm with a repetition rate of 50.2 MHz. Moreover, the signal wavelength is tuned by changing the cavity length only, and output powers up to 452 mW and pulse durations down to 268 fs are achieved. This is, to the best of our knowledge, the first demonstration of a quickly tunable femtosecond optical parametric oscillator that covers nearly the entire visible spectral range with high output power.

Kerr-lens mode locked, synchronously pumped, ultra-broadband breathing pulse optical parametric oscillator

Profiting from a breathing pulse design, we demonstrate a Kerr-lens mode locked non-collinear optical parametric oscillator, which is capable of delivering stable ultrabroadband signal spanning from 628 nm to 890 nm at -10 dB level.

High power ultra-widely tuneable femtosecond pulses from a non-collinear optical parametric oscillator (NOPO)

We present an ultra-widely tunable non-collinear optical parametric oscillator with an average output power of more than 3 W and a repetition frequency of 34 MHz. The system is pumped by the second harmonic of a femtosecond Yb:KLu(WO4)2 thin-disk laser oscillator. The wavelength of the signal pulse can be rapidly tuned over a wide range from the visible to the NIR just by scanning the resonator length.

High-efficiency parametric oscillation and spectral control in the red spectral region with periodically poled KTiOPO_4

Narrow-linewidth optical pulses at wavelengths near 630 nm with 2.2-mJ energy were generated with 61% efficiency in a periodically poled KTiOPO(4) parametric oscillator pumped by a frequency-doubled Q -switched Nd:YAG laser. The tuning range was extended to 30 nm by a noncollinear elliptical pumping geometry. We demonstrate that by angular dispersion a noncollinear optical parametric oscillator can be used to control the spectral and spatial characteristics of the output signal beam.

Broadly tunable noncollinear optical parametric oscillator with periodically poled KTiOPO4

ABSTRACT Here we report on a noncollinear optical parametric oscillator (OPO) in periodically poled KTiOPO4. The noncollinear OPOcavity consisted of a 10 mm-long periodically poled KTiOPO4 crystal placed between two flat mirrors and pumped at532nm by a frequency doubled Q-switched Nd:YAG. The OPO threshold for the collinear configuration was reached at thepump pulse energy of 10 jtJ and increased monotonically when increasing the noncolinear interaction angle. The efficiencyof the OPO with PPKTP reached 50% in the collinear configuration and about 40% in the noncollinear configuration. Thenoncollinear OPO generated two signal-idler pairs. Only one of the waves in each pair was resonated in the OPO cavity,while the complementary waves were generated at different angles as required by momentum conservation. The OPO could be tuned over a range of about 290 nm around 1064 nm wavelength by adjusting the cavity angle and the PPKTP temperature. Narrowing of the OPO spectrum was observed for small noncollinear interaction angles.Keywords: Nonlinear optical materials, Periodically poled KTiOPO4, Optical parametric oscillators, Noncollinearinteractions.