lithium niobateLiNbO3
PPLN Λ = 18.99 µm · 1550 → 775 nm · 2 px/µm
lithium niobate / 06 Devices / 6.5

6.5 Optical parametric amplifiers and oscillators

L1 Phenomenon

Run frequency doubling backwards: a strong pump splits into two lower-energy photons, amplifying a weak signal. Put that gain inside a ring and it oscillates once gain beats loss, producing tunable light at colors no laser diode emits.

OPO, triply resonant, 775 nm pump, degenerate 1550 nmclassical steady state; spontaneous emission not drawn
1101001000100000.0010.010.1110100100010000on-chip pump power (µW)signal output (µW)Pthoutput 0 below thresholdreported thresholds
Pth    23.31 µWsignal    12.49 µWoscillating
 1.00e6
 1.000 MHz
  100.00 µW
Coupling
Pth = ℏωpκp2κsκi / (16 g2κp,ex) derived; all three modes share the intrinsic Q; under / over coupling = Qi/Qc 0.5 / 2 template. g is a display range (PPLN rings: g/2π about 1.2 MHz reported). Ticks at the bottom: reported on-chip thresholds reported reported reported (bar: "tens of µW").
pump 775 nmsignal + idler 1550 nm (false color)
Threshold   23.31 µW
Signal output
   12.49 µW
State
oscillating
  100.00 µW
 1.00e6
 1.000 MHz
Coupling
1101001000100000.0010.010.1110100100010000on-chip pump power (µW)signal output (µW)Pthoutput 0 below thresholdreported thresholds
The ring lights exactly at the computed threshold. Classical steady state; spontaneous emission not drawn. Pth = ℏωpκp2κsκi / (16 g2κp,ex) derived; all three modes share the intrinsic Q; under / over coupling = Qi/Qc 0.5 / 2 template. g is a display range template (PPLN rings: g/2π about 1.2 MHz reported). Ticks: reported on-chip thresholds reported reported reported. Pump at 775 nm in spectral color, signal and idler at 1550 nm in false color.

L2 Devices and values

DeviceValueSource
Dispersion-engineered PPLN OPA, fs pump> 50 dB/cm phase-sensitive gain (6 mm); > 100 dB/cm over 600 nm near 2 µmreported
Quasi-static OPA71 dB (118 dB/cm) unsaturated, 1700-2700 nm, 4 pJ pump; 88 dB (> 146 dB/cm) saturatedreported
CW ring OPOthreshold about 30 µW; 11% conversion at 93 µWreported
CW microdisk OPO (PLACE)threshold 19.6 µWreported
Ring SHG + OPOthreshold tens of uW; tuning over 1 THz with pump detuning of hundreds of MHzreported
Pulsed tunable OPO1.53-3.25 µm on one chipreported
fs OPO comb1.5-3.3 µmreported
Mid-IR OPO, LN on sapphire> 25 mW at 3.2 µm; 15% power, 45% quantum efficiencyreported
Electrically tuned mid-IR OPO22 THz span, 2.7-3.4 µmreported
FM-OPO comb> 93% internal pump-to-comb (34% out-coupled), about 200 modesreported
All-optical switchingtens of fJ, 18 fsreported

L3 Threshold model and comparability

  • In the coupled-mode model the OPO threshold falls with the square of the nonlinear coupling rate and with the resonator quality factors (derivation: chapter 2.4). Reported thresholds are on-chip pump powers with coupling loss removed, as stated by each paper.
  • Gain in dB/cm from fs pumps is a peak-power figure; it is not comparable to CW gain.

Sources

12 cited in 6.5
RefTitleLink
Gao et al. 2021Broadband highly efficient nonlinear optical processes in on-chip integrated lithium niobate microdisk resonators of Q-factor above 10^8doi:10.1088/1367-2630/ac3d52
Guo et al. 2022Femtojoule femtosecond all-optical switching in lithium niobate nanophotonicsdoi:10.1038/s41566-022-01044-5
Hwang et al. 2023Mid-infrared spectroscopy with a broadly tunable thin-film lithium niobate optical parametric oscillatordoi:10.1364/OPTICA.502487
Hwang et al. 2026Ultra-wideband electrically tuned mid-infrared on-chip parametric oscillatordoi:10.1038/s41566-026-01999-9
Jankowski et al. 2022Quasi-static optical parametric amplificationdoi:10.1364/OPTICA.442550
Ledezma et al. 2022Intense optical parametric amplification in dispersion-engineered nanophotonic lithium niobate waveguidesdoi:10.1364/OPTICA.442332
Ledezma et al. 2023Octave-spanning tunable infrared parametric oscillators in nanophotonicsdoi:10.1126/sciadv.adf9711
Lu et al. 2020Toward 1% single-photon anharmonicity with periodically poled lithium niobate microring resonatorsdoi:10.1364/OPTICA.403931
Lu et al. 2021Ultralow-threshold thin-film lithium niobate optical parametric oscillatordoi:10.1364/OPTICA.418984
McKenna et al. 2022Ultra-low-power second-order nonlinear optics on a chipdoi:10.1038/s41467-022-31134-5
Roy et al. 2023Visible-to-mid-IR tunable frequency comb in nanophotonicsdoi:10.1038/s41467-023-42289-0
Stokowski et al. 2024Integrated frequency-modulated optical parametric oscillatordoi:10.1038/s41586-024-07071-2