Sub-50 ps pulses at 620 nm obtained from frequency doubled 1240 nm diamond Raman laser

Energy scaling of the 1st Stokes oscillation is compared in micro-lensed and plane-plane monolithic diamond Raman lasers under 532 nm pumping. A maximum Raman pulse energy of 92 µJ at 573 nm was achieved with the micro-lensed device, while in a plane-plane configuration the maximum Raman pulse energy was 3.1 mJ. 2nd Stokes generation at 620 nm in 2 and 1 mm long micro-lensed monolithic diamond Raman lasers is also reported. The best conversion efficiency from the pump at 532 nm, namely 63 %, was observed in a 2 mm long crystal at the pump pulse intensity of 4.5 GW/cm 2. By measuring the output Raman laser beam caustic it was found that the 2nd Stokes intracavity beam radius at the output coupler of the micro-lensed device is at least two times smaller than that expected from the ABCD matrix calculations of the resonator mode. A Raman gain-guiding mechanism is suggested to explain this difference.

show abstract

“…The highest pulse energy reported so far from a DRL operating in the visible spectral range [16][17][18]20] is 0.3 mJ [20].…”

Section: A 1 St Stokes Emission Energy Scalingmentioning

confidence: 99%

Energy Scaling, Second Stokes Oscillation, and Raman Gain-Guiding in Monolithic Diamond Raman Lasers

Savitski

Demetriou

Reilly

et al. 2018

IEEE J. Quantum Electron.

View full text Add to dashboard Cite

show abstract

“…More generally, excitation wavelength between 570-590 nm could be good choice if samples containing other edible oils, biodiesel or diesel are measured [36]. For both examples above, a very suitable excitation wavelength can be produced with a diamond Raman laser: 573 nm for samples containing oils and 620 nm for samples including hemoglobin [37], [38].…”

mentioning

confidence: 99%

Time-Resolved Raman Spectrometer With High Fluorescence Rejection Based on a CMOS SPAD Line Sensor and a 573-nm Pulsed Laser

Talala

Kaikkonen

Keränen

et al. 2021

IEEE Trans. Instrum. Meas.

Self Cite

View full text Add to dashboard Cite

A time-resolved Raman spectrometer is demonstrated based on a 256×8 CMOS SPAD line sensor and a 573 nm fiber-coupled diamond Raman laser delivering pulses with duration below 100 ps FWHM. The collected back scattered light from the sample is dispersed on the line sensor using a custom volume holographic grating having 1800 lines/mm. Efficient fluorescence rejection in the Raman measurements is achieved due to a combination of time gating on sub-100 ps-time scale and a 573 nm excitation wavelength. To demonstrate the performance of the spectrometer, fluorescent oil samples were measured. For organic sesame seed oil having a continuous wave mode fluorescence-to-Raman ratio of 10.5 and a fluorescence lifetime of 2.7 ns, a signal-to-distortion value of 76.2 was achieved. For roasted sesame seed oil having a continuous wave mode fluorescence-to-Raman ratio of 82 and a fluorescence lifetime of 2.2 ns, a signal-to-distortion value of 28.2 was achieved. In both cases, the fluorescence-to-Raman ratio was reduced by a factor of 24-25 owing to time gating. For organic oil, spectral distortion was dominated by dark counts while for the more fluorescent roasted oil, the main source of spectral distortion was timing skew of the sensor. With the presented post-processing techniques, the level of distortion could be reduced by 88-89 % for both samples. Compared to common 532 nm excitation, approximately 73 % lower fluorescence-to-Raman ratio was observed for 573 nm excitation when analyzing the organic sesame seed oil. Index Terms-Fluorescence rejection, Raman laser, Raman spectrometer, Raman spectroscopy, SPAD sensor, time-correlated single photon counting, time gating, timing skew I. INTRODUCTION AMAN spectroscopy is used in a wide range of fields including food and oil industries, mining industry, medical diagnostics, pharmacy, forensic science and archaeometry [1]

show abstract

“…Following a trend in recent NLO conferences as well as in the photonics community, ultrafast NLO plays an prominent role, including frequency comb generation [1][2][3], mode-locking of lasers [4], pulse compression [5] and ultrafast spectroscopy [6]. Another central theme of NLO with significant application impact as well as representation in this issue is the generation of new wavelengths, via second order nonlinearities [7][8][9][10] or Raman processes [2,11,12]. Applications also enter biomedical areas, as an exciting contribution on ultrafast laser-based refractive index modifications for ophthalmic devices [13] demonstrates.…”

mentioning

confidence: 99%

Introduction: Nonlinear Optics (NLO) 2017 feature issue

Hagan

Denz²,

Suchowski

et al. 2018

Opt. Express

View full text Add to dashboard Cite

show abstract

Sub-50 ps pulses at 620 nm obtained from frequency doubled 1240 nm diamond Raman laser

Cited by 9 publications

References 20 publications

Energy Scaling, Second Stokes Oscillation, and Raman Gain-Guiding in Monolithic Diamond Raman Lasers

Energy Scaling, Second Stokes Oscillation, and Raman Gain-Guiding in Monolithic Diamond Raman Lasers

Time-Resolved Raman Spectrometer With High Fluorescence Rejection Based on a CMOS SPAD Line Sensor and a 573-nm Pulsed Laser

Introduction: Nonlinear Optics (NLO) 2017 feature issue

Contact Info

Product

Resources

About