Strong light-matter coupling in ultrathin double dielectric mirror GaN microcavities

Abstract

Strong light-matter coupling is demonstrated at low temperature in an ultrathin GaN microcavity fabricated using two silica/zirconia Bragg mirrors, in addition to a three-period epitaxial ͑Al,Ga͒N mirror serving as an etch stop and assuring good quality of the overgrown GaN. The / 2 cavity is grown by molecular beam epitaxy on a Si substrate. Analysis of angle-resolved data reveal key features of the strong coupling regime in both reflectivity and transmission spectra at 5 K: anticrossing with a normal mode splitting of 43Ϯ 2 meV and 56Ϯ 2 meV for reflectivity and transmission, respectively, and narrowing of the lower polariton linewidth near resonance.

Polariton condensation phase diagram in wide-band-gap planar microcavities: GaN versus ZnO

“…When removing band-to-band absorption in the simulation in order to reveal the UPB, the Rabi splitting values are estimated to be equal to 80±10 and 160±10 meV for the GaN and ZnO MCs, respectively. Note that the Rabi splitting corresponding to the GaN MC is rather high compared to other structures [46][47][48] due to the use of a thick active layer, but close to the recently measured value of 84 meV in GaN MC with III-nitride air-gap DBRs 49 . In order to evaluate the excitonic and photonic weights of the cavity polaritons, a 2x2 coupled oscillator model 50 is used, from which the exciton-photon detuning (δ) is derived.…”

Patterned silicon substrates: A common platform for room temperature GaN and ZnO polariton lasers

“…7,8,9,10,11 Unfortunately, inserting a high crystalline quality material in between two dielectric amorphous DBRs requires complex processing steps. 7,8,10,11 Instead, DBRs made of semiconductor materials epitaxially grown on a crystalline substrate should enable to maintain a high crystalline quality, but require in turn a much larger number of pairs to obtain Qs similar to those achievable with dielectric materials. 12 The nitrides family (AlInGaN) seems to be more promising for fabricating the DBR than the (ZnMgCdO) one, as it presents a larger refractive index contrast within the family while keeping the same crystalline phase (i.e.…”

Strong light-matter coupling in bulk GaN-microcavities with double dielectric mirrors fabricated by two different methods

“…17 Strong light-matter coupling was not demonstrated in any of the above double dielectric MCs but we have recently reported a "double dielectric plus epitaxial" mirror MC fabricated using silicon substrate removal in which the strong coupling regime was verified at 5 K through angle-dependent reflectivity and transmission measurements. 11 In the present work, we describe another route for the fabrication of such MCs and compare the optical properties of the cavity thus obtained with those of the cavity reported in Ref. 11.…”

“…11 In the present work, we describe another route for the fabrication of such MCs and compare the optical properties of the cavity thus obtained with those of the cavity reported in Ref. 11.…”

“…Alternatively, III-nitride MCs with two dielectric DBR mirrors offer the potential for broad stop-bands, higher finesse MCs, reduced cavity length and larger exciton-photon coupling. 11 There are a number of significant difficulties to overcome, however, in fabricating a high-quality double dielectric DBR III-nitride MC. The inclusion of the second, lower dielectric DBR requires removal of the substrate in order to access the underside of the active region [12][13][14][15][16][17][18] ͓apart from one demonstration using lateral overgrowth above a stripe patterned dielectric DBR ͑Ref.…”