1 Optically pumped light emitting diodes (OP LEDs) Specifications (T=24 0C) Type No. MIRO36-xx-xxxxx series λ Peak wavelength Spectral FWHM, Pulse duration τ Pulse period T μm 3.6±0.1 μm 0.60÷0.65 ≤10 μs Pulse conditions: ≥1000 Maximum pulse current Ipulse mA 1000 Pulse voltage at I=1000 mA Upulse V 2.1÷2.8 Pulse power at I=1000 mA Ppulse μW 300±40 Maximum CW current (with a heatsink) Icw mA 50 CW voltage at I=50 mA Ucw V 1.30÷1.4 CW power at I=50 mA PCW μW 25±4 dλ/dT nm/K -3.1 dP/dT %/K -(0.6÷0.7) Package House code Lens type TO18 - TO18 mIL TO39 - TO39 IL Lens material Chalcogenide glass CdSb or Si Emission size Angle of view FWHM mm deg ∅ 0.8 ≤140 -25 to +55 -25 to +50 short leg or key is negative ∅ 1 ≤50 -25 to +50 -25 to +45 the same ∅ 0.8 ≤140 -25 to +55 -25 to +50 the same ∅ 3.5 ≤35 -25 to +50 -25 to +45 the same Type No. MIRO36-140-18s MIRO36-50-18GmL (TO18) Package photo (TO18+mIL) Storage conditions 0 Operation conditions Polarity 0 C C MIRO36-140-39s MIRO36-50-39GmL MIRO36-35-39CL (TO39) (TO39+mIL) (TO39+IL) 2 General characterization Current dependence of the output power (L-I) (24 0 C) Pulse power (mW) Pulse power (mW) 0.30 TO39 attached to a heatsink 0.4 0.3 0.2 o 24 C, f=2 kHz τ=10 μs τ=50 μs τ=250 μs 0.1 0.0 0 0.20 0.15 o 24 C, f=2 kHz τ=10 μs τ=50 μs τ=250 μs 0.10 0.05 0.00 200 400 600 800 1000 1200 1400 1600 TO18 attached to a heatsink 0.25 0 200 600 800 1000 0.20 Pulse power (mW) TO39 without a heatsink 0.25 0.20 0.15 o 24 C, f=2 kHz τ=10 μs τ=50 μs τ=250 μs 0.10 0.05 0 200 400 600 800 1000 TO18 without a heatsink 0.15 0.10 o 24 C, f=2 kHz τ=10 μs τ=50 μs τ=250 μs 0.05 0.00 0 Current (mA) 100 200 300 400 500 Current (mA) Maximal current vs. operation conditions 3000 Duty cycle = τ/T, τ - pulse duration, 2000 T - period duration Maximum current, mA Pulse power (mW) 0.30 0.00 400 Current (mA) Current (mA) 1000 900 800 700 600 500 400 300 200 TO39 attached to a heatsink TO39 without and TO18 with a heatsink TO18 without a heatsink 100 90 80 70 60 50 0.01 0.1 Duty cycle 1 600 3 Current dependence of the emission spectra(24 3.0 2.5 2.0 1.5 100 mA 500 mA 1000 mA 2000 mA 0.5 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) 1.0 1.0 o 24 C, f=2 kHz, τ=5 μs 0.5 Normalized intensity Intensity (arb.un.) 100 mA 500 mA 1000 mA 0.5 100 mA 1000 mA 2000 mA 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) 2.0 TO18 without a heatsink TO18 attached to a heatsink o 24 C, f=2 kHz, τ=5 μs 1.0 1.5 C, f=2kHz, τ=5 μs) 1.0 TO18 attached to a heatsink Normalized intensity Intensity (arb.un.) 3.5 0 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) 0.5 TO18 without a heatsink 100 mA 500 mA 1000 mA 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) Normalized emission spectra at maximal current(24 TO18 attached to a heatsink o 24 C, f=2 kHz, 0.5 τ=50 μs I=500 mA Normalized intensity Normalized intensity C) 1.0 1.0 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) o 24 C, f=2 kHz, 0.5 τ=50 μs I=250 mA 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) o 0.5 24 C, f=2 kHz, τ=250 μs I=150 mA 1.0 Normalized intensity TO18 without a heatsink TO18 attached to a heatsink 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) 1.0 Normalized intensity 0 TO18 without a oheatsink 24 C, f=2 kHz, τ=250 μs 0.5 I=100 mA 0.0 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 Wavelength (μm) 4 3.80 1.5 3.75 1.4 Power at fix. current Peak wavelength (μm) Emission spectra and output power vs. temperature 3.70 3.65 3.60 3.55 3.50 1.3 1.2 1.1 1.0 0.9 0.8 3.45 -20 -10 0 10 20 30 40 50 -20 -10 0 10 20 30 40 50 Temperature (C) Temperature (C) 500 3000 400 2500 Current (mA) Current (mA) Current-voltage (I-V) characteristics 300 200 100 0 2000 1500 1000 500 1.2 1.3 1.4 1.5 1.6 0 1.0 1.7 1.5 2.0 2.5 3.0 3.5 4.0 Voltage (V) Voltage (V) Far-field pattern 1.0 1.0 1.0 Lens type: IL FWHM=34 deg. Lens type: miL FWHM=50 deg Intensity, arb. units 0.8 0.6 0.5 0.5 No lens FWHM=140 deg 0.4 0.2 0.0 -90 -60 -30 0 30 Angle, deg. 60 90 0.0 -90 -60 -30 0 30 Angle, deg. 60 90 0.0 -90 -60 -30 0 30 Angle, deg. 60 90 5 Several useful notes Microimmersion lenses (mIL) are made from chalcogenide glass with low melting temperature (60-70oC). That’s why, please, try to install them vertically, pay attention to heasinking conditions and avoid any heaters close to the miL-LEDs. Maximum operating current is defined as that producing Δt=10-20 K overheating of the p-n junction relative to a heatsink temperature. We recommend not exceeding 0.75×Imax for long term operating devices. In certain applications it’s important to know that in addition to mid-IR radiation most optically pumped LEDs emit NIR pumping radiation λ≅0.87 μm as well (see graph on the right). This “parasitic” emission can be cut off by filters or by a detector window, e.g. by CdSb lens in TO-39 packed LEDs. Intensity (arb.un.) 1.0 0.5 0.0 0.80 0.85 0.90 0.95 Wavelength (μm) Don’t touch the chip, connecting wires and miL surface. Answers to frequently asked questions Q: What are the advantages of the IL and mIL package? A: OP LEDs with immersion lenses emit radiation within small spatial angle, so it is easier to get a signal at some distance from the LED. Q: What is the main difference between LEDs with microimmersion lens (mIL) and LEDs with immersion lens (IL)? A: miL LEDs are brighter/smaller than the L-equipped LEDs and thus standard detectors with 1×1 mm2 area can be used (spherical mirror or close “face-to-face” schemes). However, IL LEDs are more stable than the mil LEDs with respect to heating and high drive currents.