Single-photon controlled phase shifts with colloidal quantum dots at room temperature

Published Sep 24, 2026 on Dryad. https://doi.org/10.5061/dryad.63xsj3vgr

Data files

Sep 24, 2026 version files 1.71 MB

data_aee1340_for_SA_Sept_CC0.zip

1.69 MB
README.md

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Abstract

This dataset provides the experimental data supporting a study on controllable phase shifts realized with colloidal quantum dots (CQDs) coupled to a hybrid microcavity at room temperature. The deposited files include the measured raw data, such as spectral data, interference data recorded at various probe wavelengths, and interference data measured under different pump powers.

The dataset relates to a platform in which a dielectric photonic-crystal-based hybrid microcavity is strongly coupled with CQDs, including both a single CQD positioned by a soft nano-probe technique and a high-concentration CQD ensemble. Combining photoluminescence spectroscopy, Michelson interferometry, and continuous-wave pump–probe measurements, the dataset records the phase response of the coupled system as a function of probe wavelength and pump power. Controlled π phase shifts at the single-photon level were obtained in both the single-CQD and high-concentration CQD systems. These data are intended to support the analysis and reproduction of the reported phase-shift behavior, and may be useful for the development of room-temperature quantum optoelectronic devices, such as quantum phase gates and low-power optical switches.

Authors: Xingsheng Xu^*, Chai Hu

*Email: xsxu@semi.ac.cn

Dataset DOI: 10.5061/dryad.63xsj3vgr

Dataset Description of the data and file structure

The dataset is in: data_aee1340_for_SA_Sept_CC0.zip

DRYAD data description for Science Advances submission (MS no:aee1340):

Dataset Overview: This dataset contains the experimental data on controllable phase shifts achieved using colloidal quantum dots (CQDs) at room temperature.

Files with the extension ".txt" or “lvm” contain the measured raw data, including measured spectral data (Fig. 1), measured interference data at different wavelengths (Figs. 2 and 4), and measured interference data under different pump powers (Figs. 3 and 4).

The raw data for each figure includes:

The contents of the "data to upload" dataset are described below in the order of the folders from top to bottom:

1. The folder named "FIG 1" introduces the raw data.

The subfolder Fig. 1D contains the photoluminescence (PL) spectra of the strong coupling between 800 nm CQDs and the PC-FP cavity under different pump powers. The raw measurement data are stored in the secondary subfolder "Data for Fig.1D", which from top to bottom contains the PL spectra measured at laser powers of 1000 μW, 18.4 μW, and 98 μW. The corresponding names of the files are: Pump power-1mW_532nm Focus-PL.txt, Pump power-98uW_532nm Focus-PL.txt, and Pump power-18.4uW_532nm Focus-PL.txt.

The data processing methods and results are shown in the Origin file "Fig.1D_dealing include data and code.opju", which is located under the Supplementary_Information category in Zenodo. The following data processing is similar.

2. The folder named "FIG 2" introduces the experimental optical path and phase change measurement results of the high-concentration CQDs-FP system.

The subfolder "Data for Fig.2B-D" contains the interference data measured at different probe wavelengths. The corresponding probe wavelengths are 780.33 nm, 775.32 nm, 770.14 nm, 764.81 nm, 760.32 nm, 755.31 nm, 750.29 nm, 745.5 nm, 740.3 nm, 770.34 nm, 772.4 nm, 774.75 nm, 776.41 nm, 778.16 nm, 780.41 nm, 782.49 nm, 784.40 nm, 786.57 nm, 789.9 nm, 795.81 nm, 800.55 nm, 805 nm, 810.13 nm, 815.11 nm, 820.27 nm, 825.76 nm, and 830.76 nm. The corresponding data file names include information of the probe wavelength, such as: SiN-PC-SU8-800CQDs_probe 780.33nm_inteference data_002.lvm, et al. The file of *.lvm can be open as text file.

3. The folder named "FIG 3 and FIG S2-S5" shows the variation of the controlled phase shift in the CQDs-FP-cavity strong-coupling system under pump of 532nm CW laser with different pump powers.

(1) The folder \Data for Fig.3_high contration CQDs_varying power-interference\770nm probe

This folder contains the raw measurement data of the controlled phase shift in the CQDs-FP cavity strong-coupling system at different pump powers, for probe wavelengths of 770 nm. The raw data files name and corresponding pump powers are described as follows:

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_001.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0, 3.82, 6.82, 10.94, and 16.84 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_002.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 16.84, 22.88, 30.06, 38.66, and 48.6 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_003.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 48.6, 59.4, 66.2, 74.4, and 84.2 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_004.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 84.2, 98.8, 118, 140, and 158.2 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_005.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 158.2, 167, 178.8, 187, and 197.6 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_006.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 197.6, 208, 219.4, 242, 266 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_007.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 266, 281, 309.4, 329.8, 342 μW.

SiN-PC-SU8-800CQDs_probe780nm_pump532nm_inteference data_008.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 342, 380.6, 418.6, 459.4, 487 μW.

For each probe wavelength, the last segment of one group and the first segment of the next group share the same pump power, serving as repeated measurements to ensure continuity between the two groups.

(2) The folder \Data for Fig.3_high contration CQDs_varying power-interference\780nm probe, contains the raw measurement data of the controlled phase shift in the CQDs-FP cavity strong-coupling system at different pump powers, for probe wavelengths of 780 nm. The raw data files name and corresponding pump powers are described as follows:

SiN-PC-SU8-800CQDs_probe 780nm_pump_532nm_01.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0, 3.88, 7.4, 12.22, 17.4 μW.

SiN-PC-SU8-800CQDs_probe 780nm_pump_532nm_02.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 17.4, 25.2, 40.4, 61.8, 89.4 μW.

SiN-PC-SU8-800CQDs_probe 780nm_pump_532nm_03.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 89.4, 117.4, 152.6, 182.6, 232.8 μW.

SiN-PC-SU8-800CQDs_probe 780nm_pump_532nm_04.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 232.8, 270.6, 311.4, 376.8, 400.6 μW.

(3) The folder \Data for Fig.3_high contration CQDs_varying power-interference\793nm probe, contains the raw measurement data of the controlled phase shift in the CQDs-FP cavity strong-coupling system at different pump powers, for probe wavelengths of 793nm.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_01.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0, 4.72, 10.62, 19.76, 26.28 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_02.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 26.28, 36.02, 42.8, 52.8, 61.2 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_03.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 61.2, 74.2, 89.8, 101, 113.6 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_04.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 113.6, 125, 146, 171.6, 189 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_05.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 189, 222.4, 244.2, 306.2, 332.4 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_06.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 500, 656, 824, 1012, 1286 μW.

(4) The folder \Data for Fig.3_high contration CQDs_varying power-interference\830nm probe, contains the raw measurement data of the controlled phase shift in the CQDs-FP cavity strong-coupling system at different pump powers, for probe wavelengths of 830 nm.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_002.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0, 4.74, 20.16, 42.3, 64 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_003.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 64, 82.8, 112.2, 136.8, 160 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_004.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 160, 189.4, 227.2, 312, 436.6 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_005.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 436.6, 521.2, 633.2, 729.2, 865.2 μW.

SiN-PC-SU8-800CQDs_probe 793nm_pump_532nm_006.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 865.2, 927.2, 1075.2, 1155.2 μW.

4. The folder named "FIG 4 and FIG S7-S9" shows the controlled phase shift of the strong-coupling system formed by a single CQD and a PC-FP cavity.

(1) The subfolder "Data for Fig.4_spectrum for single CQD" contains the measurement data of the emission spectrum of a single quantum dot. The measurement parameter settings are detailed in the text file named "800QD E-8-toujing on-P1-111uW_Pump-532 focus-PL.txt": the pump wavelength is 532 nm and the power is 111 μW. The Origin file named "PL_single QD" shows the emission spectrum of the single quantum dot.

(3) The subfolder "Data for Fig.4_varying wavelength" contains the raw measurement data of the relative phase variation with probe wavelength; the corresponding probe wavelengths in the raw data files are detailed as follows.

220nmSiN_2000r SU8 2002-800QD singleQD_001.lvm, corresponding probe wavelength:780，778，776，774nm, where the interference data consists of four segments measured sequentially with almost equal acquisition time.

220nmSiN_2000r SU8 2002-800QD singleQD_002.lvm, corresponding probe wavelength:774，772，770，768，766nm.

220nmSiN_2000r SU8 2002-800QD singleQD_003.lvm, corresponding probe wavelength:766，765，762，760，758nm.

220nmSiN_2000r SU8 2002-800QD singleQD_004.lvm, corresponding probe wavelength:758，756，754，752，750nm.

220nmSiN_2000r SU8 2002-800QD singleQD_005.lvm, corresponding probe wavelength:750，745，740，735，780nm.

220nmSiN_2000r SU8 2002-800QD singleQD_006.lvm, corresponding probe wavelength: 780，782，784，786，788nm.

220nmSiN_2000r SU8 2002-800QD singleQD_007.lvm, corresponding probe wavelength: 788，790，792，794，796nm.

220nmSiN_2000r SU8 2002-800QD singleQD_008.lvm, corresponding probe wavelength: 796，798，800，802，806nm.

220nmSiN_2000r SU8 2002-800QD singleQD_009.lvm, corresponding probe wavelength: 806，812，818，824，830nm.

(2) The subfolder "Data for Fig.4_varying power" contains the raw measurement data of the controlled phase shift in the single CQD-FP cavity strong-coupling system at different pump powers, for probe wavelengths of 770 nm, 780 nm, and 790 nm, respectively. The pump power values in the raw data files are described as follows.

Data for Fig.4_varying power\770nm

SiN-PC-SU8-800CQD single QD_probe 770nm_pump532_001.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0，0.76，1.96，3.6，5.48μW.

SiN-PC-SU8-800CQD single QD_probe 770nm_pump532_002.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 5.48，7.44，8.52，10.76，13.68μW.

SiN-PC-SU8-800CQD single QD_probe 770nm_pump532_003.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 13.68，17.8，22，25.2，28.64μW.

SiN-PC-SU8-800CQD single QD_probe 770nm_pump532_004.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 28.64，32.6，5.36，37.96，40.96μW.

SiN-PC-SU8-800CQD single QD_probe 770nm_pump532_005.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 40.96，43.08，44.84，47.76，51.24μW.

Data for Fig.4_varying power\780nm

SiN-PC-SU8-800CQD singleQD_probe 780nm_pump532_010.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0，1.2，2.16，3.2，4.12μW.

SiN-PC-SU8-800CQD singleQD_probe 780nm_pump532_011.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 4.12，4.88，6，6.88，8.04μW.

SiN-PC-SU8-800CQD singleQD_probe 780nm_pump532_012.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 8.04，8.84，10.16，11.48，12.16μW.

SiN-PC-SU8-800CQD singleQD_probe 780nm_pump532_013.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 12.16，13.08，14.44，16.12，17.72μW.

SiN-PC-SU8-800CQD singleQD_probe 780nm_pump532_014.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 17.72，18.68，19.6，21.28，23.72μW.

SiN-PC-SU8-800CQD singleQD_probe 780nm_pump532_015.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 37.76，41.96，45.2，48.36，50.68μW.

Data for Fig.4_varying power\780nm

SiN-PC-SU8-800CQD singleQD_probe 790nm_pump532_022.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 0，1.12，1.96，3.96，6.32μW.

SiN-PC-SU8-800CQD singleQD_probe 790nm_pump532_023.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 6.32，8.4，10.88，14.16，16.68μW.

SiN-PC-SU8-800CQD singleQD_probe 790nm_pump532_024.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 16.68，20.12，23.32，26.4，28.92μW.

SiN-PC-SU8-800CQD singleQD_probe 790nm_pump532_025.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 28.92，32.36，36.16，38.08，40.88μW.

SiN-PC-SU8-800CQD singleQD_probe 790nm_pump532_026.lvm, where the interference data consists of five segments measured sequentially with almost equal acquisition time for each segment at pump powers of 40.88，43.68，45.6，48.4，50.48μW.

5. The folder named "FIG S11" shows the comparative measurements of the phase shift in the absence of pumping and without CQDs.

(1) The subfolder "empty cavity" contains the raw data of the controllable phase variation measurement in an empty cavity without CQDs. The file name is: 3umSiO2_no 800QD_probe780nm_pump532nm_008.lvm, _009.lvm, and _010.lvm.

(2) The subfolder "no pump" contains the raw data of the phase variation measurement without pump light. The file name is: CQDs-no pump_interference data_001.lvm, _002.lvm, and _003.lvm.

6. The folder named "FIG S12" shows the results of two repeated measurements of the controlled phase variation in the strong-coupling system.

(1) The subfolder "high CQDs" contains the raw data of two repeated measurements performed in a high-concentration CQD-coupled microcavity, which are stored in the secondary subfolders named "The first measurement_data for interference" and "The second measurement_repeat", respectively.

(2) The subfolder "single CQD" contains the raw data of two repeated measurements performed in a single CQD-coupled microcavity; the measurement conditions of the raw data files can be described as:

The first four sets: represent the interference curves of the single quantum dot-cavity system with continuously varying pump power obtained from the first measurement；and the last three sets represent: the interference curves of the single quantum dot-cavity system with continuously varying pump power obtained from repeated measurements.

Code/software

Data processing was performed using Origin. The corresponding *.opju or *.oggu project files are provided, containing the full processing and analysis procedures.

Access information

Other publicly accessible locations of the data:

Data was derived from the following sources:

Experimental Setup

The phase shifts of a strongly coupled colloidal quantum dot (CQD)–photonic crystal (PC) Fabry–Pérot (FP) cavity system were characterized using a Michelson-type interferometric setup combined with a continuous-wave (CW) pump–probe scheme. A 532 nm CW laser served as the pump, which generated a steady-state exciton population in the CQDs and provided a stable means of controlling the strength of the light–matter interaction in the coupled system. A tunable CW laser, operating between 735 and 830 nm, was used as the probe, with its power kept at the single-photon level (3–5 nW) so that the system state was not perturbed. This strong-pump/weak-probe configuration is well suited to examining the steady-state nonlinear response of the exciton–photon system.

Optical Path Configuration

The probe beam was divided by a beam splitter into a sample arm and a reference arm. In the sample arm, the probe was focused onto the sample surface through a 100× microscope objective, and the reflected beam, which carried the phase information modulated by the coupled system, was directed back along the same path. In the reference arm, the beam was reflected by a mirror mounted on a high-precision motorized translation stage. Scanning this stage continuously varied the reference optical path length, thereby introducing a controllable phase delay. The two returning beams were recombined at the beam splitter; residual pump light was removed with a filter, and the interference signal was detected by a silicon photodetector together with a lock-in amplifier to improve the measurement sensitivity.

Measurement Procedure

For each measurement, the piezoelectric translation stage was scanned to produce a stable interference fringe pattern. The microscope objective was adjusted so that the probe was focused on the core test unit of the sample, and the translation stage was driven to match the optical path lengths of the two arms, ensuring stable interference fringes. The interference fringes recorded with and without the pump beam were fitted with a sinusoidal function; the fitted phases were then extracted, and their difference gave the pump-induced phase shift.

To characterize the spectral response, the pump beam was switched off, and the relative phase shift was recorded as a function of probe wavelength over the range of 735–830 nm. This allowed the anomalous dispersion region associated with strong coupling to be identified and the optimal probe wavelength for the subsequent power-dependent measurements to be determined. For the power-dependent measurements, the probe wavelength was fixed at a selected value, the pump power was varied, and the corresponding phase shift was recorded. The average pump photon number was derived from the measured pump power using the cavity parameters. All measurements were carried out at room temperature.

Data Processing

For the phase measurements, the reference optical path length was varied in the lateral direction by a precision motorized scanning stage, and the resulting signal was combined with the direct signal to extract the interference information. A full scan of the stage covered multiple periods, which allowed multiple data points to be fitted. The data points shown in the main text were obtained by repeatedly scanning the piezoelectric stage while the pump power was increased incrementally. Using this multi-period, repeated-accumulation procedure together with subsequent curve fitting, the controlled phase shift as a function of pump power displayed a bi-exponential dependence. For measurements at different wavelengths and pump powers, the same repeated multi-period measurement and fitting procedure consistently yielded a bi-exponential trend characteristic of nonlinear interactions, confirming the reproducibility of the controlled phase-shift behavior.