Si nanoparticles with a mean radius of 49 nm and dot density of
in
| SRS gain [dB/cm] versus pump focused power [W] | Fivefold enhancement of the Raman gain coefficient of silicon nanocomposites with respect to bulk silicon and a reduction of about 60% of threshold power | [80,81] |
-μm-diameter Si spheres | Intensity of the spontaneous Raman peak |
over the Raman intensity from bulk Si | [83] |
Composite of alternating, subwavelength-thick layers of titanium dioxide and the conjugated polymer poly(p-phenylene-benzobisthiazole) | Enhancement in
as a function of the volume fill fraction of component a (titanium dioxide). | Maximum enhancement of 35% | [84] |
Micrometer-sized water droplets | Stimulated Raman scattering (SRS) bands appear in the range
| - | [85] |
Glycerol–water microdroplets with radii in the 11–15 μm range | lasing signal | Lasing signal was higher than the background by more than 30 dB. | [86] |
Mesoscopic low-dimensional and heterogeneous structures | Theoretical investigation of photon density of states effects on spontaneous Raman scattering | | [87] |
Droplet microcavity | Stimulated Raman scattering thresholds versus microdroplet size and composition. |
in carbon disulfide (the species with the narrowest linewidth examined) | [88] |
Microcavity | Analytical relation between bulk and cavity-modified Raman gains for microcavities with arbitrary geometric shapes |
| [89] |
semiconductor planar microcavity | Spontaneous Raman enhancement versus cavity effect | Four orders of magnitude | [90] |
Raman source consisting of a high-Q silica microsphere coupled to an optical fiber (sphere gap for a 40-μm-diameter sphere,
). | Raman threshold versus coupling gap and size + pump-signal conversion (Raman power emission versus incident power) | Pump threshold 1000 times lower pump-signal
| [91] |
Spherical and toroid microcavities on-a-chip made from silica | Raman threshold versus coupling gap and size + output power versus input pump power | The lowest threshold observed value was 62 μW of launched power, which is nearly three orders of magnitude lower than for free-space illumination of microdroplets. Pump-signal
. | [92] |
Silica and barium titanate (
) microspheres | Enhancement
Raman intensity of the sample with excitation through a single microsphere to that with the direct excitation (without a microsphere) versus microsphere diameter | The maximum ER of the
and silica is found to be 35 and 83, respectively. | [93] |
Waveguide-integrated diamond racetrack microresonators | Output Stokes power versus input pump power | External conversion slope efficiency is
, corresponding to an internal quantum efficiency of
. | [94] |
Silicon microresonator | Observation of strong Raman scattering lines in the generated comb | - | [95] |
Silicon photonic-crystal waveguides | Spontaneous Raman scattering coefficient versus bulk Si | Six times | [97] |
L5 photonic bandgap nanocavities in two-dimensional (2D) photonic crystal | Theoretical Raman lasing threshold |
| [100] |
Photonic-crystal, high-quality-factor nanocavity | Raman output power versus pump power | Slope efficiency of 8% | [101] |
Macropores in single-crystalline gallium phosphide (GaP) with ore sizes of about 150 nm | Optical transmission measurements demonstrate that the nonabsorbing disordered structures strongly scatter light. | | [102] |
Increased path lengths of photons in the region with high gain due to multiple scattering. | Monte Carlo simulation of the random walk of pump and emitted photons. Spectral width versus pump fluence. | About 40 nm at pump fluence of
threshold pump power
| [103] |
Barium nitrate powder | Raman transmission gain versus thickness L of the powder layer | 6 [a.u.] | [104] |
Vesicular films activated by dyes (rhodamine 6G, pyrromethene 597) | Spectral width versus pump intensity |
at
| [105] |
powders | Transmitted and reflected probe light versus pump intensity for various sample thicknesses | Transmission: maximum
for sample
. Reflection: maximum
for sample
. | [106] |
Barium sulphate (
) powder with particle diameters of 1–5 μm | Raman energy versus pump energy | Conversion efficiency of pump photons into Raman photons was approximately 1%. | [107] |