Ruby Crystal for Demonstrating Time- and Frequency-Domain Methods of Fluorescence Lifetime Measurements

Abstract

We present experiments that are convenient and educational for measuring fluorescence lifetimes with both time- and frequency-domain methods. The sample is ruby crystal, which has a lifetime of about 3.5 milliseconds, and is easy to use as a class-room demonstration. The experiments and methods of data analysis are used in the lab section of a class on optical spectroscopy, where we go through the theory and applications of fluorescence. Because the fluorescence decay time of ruby is in the millisecond region, the instrumentation for this experiment can be constructed easily and inexpensively compared to the nanosecond-resolved instrumentation required for most fluorescent compounds, which have nanosecond fluorescence lifetimes. The methods are applicable to other luminescent compounds with decay constants from microseconds and longer, such as transition metal and lanthanide complexes and phosphorescent samples. The experiments, which clearly demonstrate the theory and methods of measuring temporally resolved fluorescence, are instructive and demonstrate what the students have learned in the lectures without the distraction of highly sophisticated instrumentation.

Spin thermometry and spin relaxation of optically detected Cr3+ ions in ruby Al2O3

“…The optical T 1,opt in ruby is well-known in literature, going back to the first measurements by Becquerel with his phosphoroscope in 1867 [1]. It stays relatively constant for temperatures below 300 K [31,32], and is in good agreement with our data.…”

Intriguing minerals: corundum in the world of rubies and sapphires with special attention to Macedonian rubies

“…As discussed above, it is well established that the presence of Cr 3+ is the cause of the pale pink colour, which turns deep red as its concentration increases [4,6,7,60]. The vibrant blue colour of sapphires (Fig.…”

Enhanced light emission from erbium doped silicon nitride in plasmonic metal-insulator-metal structures

“…The PL spectrum from the Er:SiN x layer on gold is similar to the spectrum of Er:SiN x deposited on quartz, while the total integrated intensity from the sample on the gold substrate is reduced by approximately a factor of 2. We perform lifetime measurements using the demodulation technique [24], and find that the Er:SiN x deposited on gold has a lifetime of 100 µs. We also measure the lifetime of the quartz substrate sample, both with and without a 30nm gold layer on top of the Er:SiN x layer, and observe lifetimes of 100-130 µs.…”