Showing papers on "Responsivity published in 1998"
TL;DR: In this paper, a metal-semiconductor-metal photodetector based on relaxed Ge layers, epitaxially grown on silicon after insertion of a low-temperature-grown Ge buffer layer, was presented.
Abstract: In this letter we report on a metal–semiconductor–metal photodetector based on thick relaxed Ge layers, epitaxially grown on silicon after insertion of a low-temperature-grown Ge buffer layer. The detector shows a good responsivity at normal incidence at both 1.3 and 1.55 μm, with a maximum responsivity of 0.24 A/W at 1.3 μm under a 1 V bias. A response time of about 2 ns has been measured.
249 citations
TL;DR: In this paper, the fabrication and characterization of ultraviolet photodetectors based on GaN p-n junctions is reported, which are grown by metalorganic vapour phase epitaxy on basal-plane sapphire substrates.
Abstract: The fabrication and characterization of ultraviolet photodetectors based on GaN p-n junctions is reported. The devices are grown by metalorganic vapour phase epitaxy on basal-plane sapphire substrates. These detectors are visible-blind with a sharp wavelength cut-off at 360 nm. The photocurrent is linear with incident power from up to , with a responsivity of at 360 nm. The device time response is dominated by the effective resistance-capacitance time constant, and a 105 ns response is estimated for very low load resistances. A comparison with the response of GaN photoconductor detectors is also presented. The application of these high-performance photodetectors for solar ultraviolet monitoring is described.
197 citations
TL;DR: In this paper, a flexural beam is utilized as the primary transduction mechanism for demonstrating a series of fiber Bragg grating (FBG) accelerometers, which have many desirable features including good acceleration sensitivity (212.5 /spl mu/spl epsiv/g), high resonant frequencies (on the order of 1 kHz), very low cross-axis sensitivity (< 1% of the primary axial responsivity), and low noise (/spl sim/1 mg/spl radic/(Hz) near 1 Hz).
Abstract: A flexural beam is utilized as the primary transduction mechanism for demonstrating a series of fiber Bragg grating (FBG) accelerometers. The fully packaged FBG accelerometers reported in this work have many desirable features including good acceleration sensitivity (212.5 /spl mu//spl epsiv//g), high resonant frequencies (on the order of 1 kHz), very low cross-axis sensitivity (<1% of the primary axial responsivity), and low noise (/spl sim/1 mg//spl radic/(Hz) near 1 Hz). Arrays of such devices can be utilized in a variety of applications, including structural monitoring. Closed-form analytical formulas describing the resonant frequency and responsivity of the FBG accelerometer are provided which may be utilized to tailor the sensor performance to specific applications.
179 citations
ETSI1
TL;DR: In this paper, a model to explain the behavior of GaN photoconductive detectors is proposed, and it is based on the idea of a volume modulation rather than a carrier density modulation.
Abstract: A model to explain the behaviour of GaN photoconductive detectors is proposed, and it is based on the idea of a volume modulation rather than a carrier density modulation. Space charge regions inside the semiconductor produce a variation of the conductive volume when carriers are photogenerated. The strong non-exponential photocurrent decays result from carrier capture processes over the barriers associated with space charge regions. By means of computer simulation, this model explains quite well the behaviour of current GaN photoconductor devices and predicts their time response, temperature dependence and responsivity properties.
172 citations
TL;DR: In this paper, a self-assembled InGaAs quantum dot infrared photodetector (QDIP) consisting of self assembled InGaA quantum dots has been demonstrated with a response of 325 mA/W at 92 μm.
Abstract: A quantum dot infrared photodetector (QDIP) consisting of self-assembled InGaAs quantum dots has been demonstrated Responsivity of 325 mA/W at 92 μm was obtained for nonpolarized incident light on the detector with a 45° angle facet at 60 K The QDIPs exhibit some unique electro-optic characteristics such as a strong negative differential photoconductance effect and blueshift of the response peak wavelength
164 citations
TL;DR: In this article, the authors report solar-blind AlxGa1−xN photovoltaic detectors with cutoff wavelengths as short as 290 nm, with spectral responsivity of the devices near the cutoff wavelength is 0.07 A/W.
Abstract: We report solar-blind AlxGa1−xN photovoltaic detectors with cutoff wavelengths as short as 290 nm. Mesa geometry devices of different active areas are fabricated and characterized for spectral responsitivity, speed, and noise performance. The responsivity of the devices near the cutoff wavelength is 0.07 A/W. The detector noise is found to be 1/f limited, with a noise equivalent power of 6.6×10−9 W over the total response bandwidth of 100 kHz.
147 citations
TL;DR: In this paper, the optimum growth conditions were studied to obtain uniform InGaAs quantum dots constructed in an InGaP matrix, and normal incidence photoconductivity was observed at a peak wavelength of 5.5 μm with a high responsivity of 130 mA/W and a detectivity of 4.74×107 cm/H1/2/W at 77 K.
Abstract: We report InGaAs quantum dot intersubband infrared photodetectors grown by low-pressure metalorganic chemical vapor deposition on semi-insulating GaAs substrates. The optimum growth conditions were studied to obtain uniform InGaAs quantum dots constructed in an InGaP matrix. Normal incidence photoconductivity was observed at a peak wavelength of 5.5 μm with a high responsivity of 130 mA/W and a detectivity of 4.74×107 cm H1/2/W at 77 K.
147 citations
TL;DR: In this paper, the first implementation of a terahertz detector utilizing two-dimensional (2D) electronic fluid in a high electron mobility transistor (HEMT) operating at 2.5 THz was reported.
Abstract: We report on the first implementation of a terahertz detector utilizing two-dimensional (2-D) electronic fluid in a high electron mobility transistor (HEMT) operating at 2.5 THz. The terahertz radiation induced a dc drain-to-source voltage proportional to the radiation intensity. The measured dependencies of the detector responsivity on the gate bias are in good agreement with the gate bias dependence of the normalized responsivity predicted by the detector theory. This result shows the potential for developing a new family of electronics devices-plasma wave electronics devices-operating at terahertz frequencies.
131 citations
TL;DR: In this article, the temperature dependence of the nonequilibrium carriers lifetime has been deduced from the measurement of the photocurrent response in InAs/GaSb superlattices.
Abstract: The temperature dependence of the nonequilibrium carriers lifetime has been deduced from the measurement of the photocurrent response in InAs/GaSb superlattices. Based on the temperature dependence of the responsivity and modeling of the transport parameters we have found that the carrier lifetime weakly depends on temperature in the high-temperature region. This indicates the temperature dependence of the Auger recombination rate with no threshold that differs it from that in the bulk material and can be attributed to the interface-induced suppression of the Auger recombination in thin quantum wells.
131 citations
TL;DR: In this paper, the growth and characterization of GaN p-i-n photodiodes with a very high degree of visible blindness was presented, where thin films were grown by low-pressure metalorganic chemical vapor deposition.
Abstract: We present the growth and characterization of GaN p-i-n photodiodes with a very high degree of visible blindness. The thin films were grown by low-pressure metalorganic chemical vapor deposition. The room-temperature spectral response shows a high responsivity of 0.15 A/W up until 365 nm, above which the response decreases by six orders of magnitude. Current/voltage measurements supply us with a zero bias resistance of 1011 Ω. Lastly, the temporal response shows a rise and fall time of 2.5 μs measured at zero bias. This response time is limited by the measurement circuit.
112 citations
TL;DR: In this paper, back-illuminated GaN/AlGaN ultraviolet (UV) heterojunction photodiodes with high quantum efficiencies were demonstrated, achieving photovoltaic (zero bias) responsivity of 0.2 A/W at 355 nm.
Abstract: Back-illuminated GaN/AlGaN ultraviolet (UV) heterojunction photodiodes with high quantum efficiencies are demonstrated. Photovoltaic (zero bias) responsivity of 0.2 A/W at 355 nm was achieved. The improved efficiencies primarily arise from the use of AlGaN/GaN heterojunction in which photons are absorbed within the p-n junction thus eliminates carrier losses due to surface recombination and diffusion processes in previously reported homojunction devices. Very high dark impedance and large visible rejection ratio were obtained. These results indicate high quality GaN/AlGaN interface and efficient photocarrier collection in the photodiode.
TL;DR: Gold and nickel Schottky barrier photovoltaic detectors have been fabricated on Si-doped AlxGa1−xN layers (0.22Ga0.78N/Au) grown on sapphire by metalorganic vapor phase epitaxy as mentioned in this paper.
Abstract: Gold and nickel Schottky barrier photovoltaic detectors have been fabricated on Si-doped AlxGa1−xN layers (0⩽x⩽0.22) grown on sapphire by metalorganic vapor phase epitaxy. Responsivity is independent of the Schottky metal or diode size, and also of the incident power in the range measured (10 mW/m2–2 kW/m2). A higher visible rejection has been observed in the spectral response of Au photodiodes (>103). Time response is resistance-capacitance limited, with time constants as short as 14 ns in Al0.22Ga0.78N diodes. Low frequency noise studies are also presented, and detectivities of 6.1×107 and 1.2×107 mHz1/2 W−1 are determined in GaN/Au and Al0.22Ga0.78N/Au detectors, at −2 V bias.
TL;DR: In this article, the authors used Bi4Ti3O12 (BiT) ferroelectric thin films as photoconductive or photovoltaic ultraviolet detectors and obtained a specific detectivity of 5.5×108 cm, W−1.1/2 at a modulation frequency of 20 Hz.
Abstract: Bi4Ti3O12 (BiT) ferroelectric thin films were used as photoconductive or photovoltaic ultraviolet detectors. The maximum of the spectral distribution lies around 370 or 390 nm, depending on whether the incident light is continuous or modulated. The maximum current responsivity obtained for the films annealed at 700 °C is about 0.01 A/W. The specific detectivity is 5.5×108 cm W−1 Hz1/2 at a modulation frequency of 20 Hz. The frequency characteristics of the photovoltaic signal measured in modulated light suggests a 1/f frequency dependence of this signal.
Patent•
13 Jul 1998
TL;DR: In this article, a light shield is employed above the substrate to modulate the pixel color responsivity, and the light shield forms an aperture whose area is substantially equal to the light receiving area adjusted by a reduction factor.
Abstract: A method and apparatus for employing a light shield to modulate pixel color responsivity. The improved pixel includes a substrate having a photodiode with a light receiving area. A color filter array material of a first color is disposed above the substrate. The pixel has a first relative responsivity. A light shield is disposed above the substrate to modulate the pixel color responsivity. The light shield forms an aperture whose area is substantially equal to the light receiving area adjusted by a reduction factor. The reduction factor is the result of an arithmetic operation between the first relative responsivity and a second relative responsivity, associated with a second pixel of a second color.
TL;DR: In this article, a 63-element linear arrays of micromachined thermopile infrared detectors on silicon substrates were fabricated and tested under vacuum and room temperature conditions, achieving response times of 99 ms, zero frequency D* values of 1.4/spl times/10/sup 9/ cmHz/sup 1/2/W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source.
Abstract: We have fabricated 63-element linear arrays of micromachined thermopile infrared detectors on silicon substrates. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi-Te and Bi-Sb-Te films. At room temperature and under vacuum these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4/spl times/ 10/sup 9/ cmHz/sup 1/2//W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source. The only measured source of noise above 20 mHz is Johnson noise from the detector resistance. These results represent the best performance reported to date for an array of thermopile detectors. A test procedure is described that measures many of the relevant electrical, optical, and thermal properties of the detectors without specialized test structures.
TL;DR: In this article, the authors demonstrate the longest (λc=28.6 μm) far-infrared quantum well photodetectors (QWIPs) based on a bound-to-bound intersubband transition in GaAs/AlGaAs.
Abstract: We demonstrate the longest (λc=28.6 μm) far-infrared quantum well photodetectors (QWIPs) based on a bound-to-bound intersubband transition in GaAs/AlGaAs. The responsivity is comparable with that of mid-infrared GaAs/AlGaAs and InGaAs/GaAs QWIPs. A peak responsivity of 0.265 A/W and detectivity of 2.5×109 cmHz/W at a wavelength of 26.9 μm and 4.2 K have been achieved. Based on the temperature dependent dark current and responsivity results, it is expected that similar performance can be obtained at least up to 20 K.
TL;DR: Good agreement at the level of 2 x 10(-3) in the visible wavelength range verifies that the reflection model can be used for accurate extrapolation of the spectral reflectance and responsivity of silicon photodiode devices.
Abstract: A precision spectrometer was used to measure the spectral reflectance of a silicon photodiode over the wavelength range from 250 to 850 nm. The results were compared with the corresponding values predicted by a model based on thin-film Fresnel formulas and the known refractive indices of silicon and silicon dioxide. The good agreement at the level of 2 × 10-3 in the visible wavelength range verifies that the reflection model can be used for accurate extrapolation of the spectral reflectance and responsivity of silicon photodiode devices. In addition, characterization of the photodiode reflectance in the ultraviolet region improves the accuracy of the spectral irradiance measurements when filter radiometers based on trap detectors are used.
TL;DR: In this article, pyroelectric infrared detectors based on semiconducting Y-Ba-Cu-O have been investigated, with a wide range of values of the values with the maximum close to 20μC/cm2
Abstract: Uncooled pyroelectric infrared detectors based on semiconducting Y–Ba–Cu–O have been investigated. Samples with four different structures were characterized. Two of the pyroelectric detectors were thermally isolated from the substrate by micromachining techniques for high optical sensitivity. Pyroelectricity was observed by the methods of optical illumination and direct substrate heating. A wide range of the values of pyroelectric coefficients was obtained with the maximum close to 20 μC/cm2 K in one device. Detectivities up to 108 cm Hz1/2/W were measured. The temperature dependence of these pyroelectric sensors was investigated. It was found that one device showed a fairly constant optical response with respect to temperature over a wide range around 300 K. However, responsivity of another device of a different geometry decreased sharply at ∼304 K. The spectral study of these devices showed that the wavelength-dependent response decreased when the silicon transmission increased. In addition, frontside i...
TL;DR: The first experimental realization of a multifunctional long wavelength /spl lambda/=1.5/spl mu/m InGaAsP MQW vertical cavity laser amplifier-photodetector was reported in this article.
Abstract: We report on the first experimental realization of a multifunctional long wavelength /spl lambda/=1.5-/spl mu/m InGaAsP MQW vertical cavity laser amplifier-photodetector. An optical gain of up to 18 dB and a voltage responsivity of 160 V/W is demonstrated.
TL;DR: Theresponsivity of the photodetectors consisting of the large-areaphotodiodes reached saturation at higher photocurrent values compared with the devices based on the photmodiodes with smaller active area.
Abstract: Nonlinearities of the responsivity of various types of siliconphotodetectors have been studied. These detectors are based onphotodiodes with two sizes of the active area (10 x 10 mm(2) and 18 x 18 mm(2)). The detectorconfigurations investigated include single photodiodes, two reflectiontrap detectors, and a transmission trap detector. For all devices, the measured nonlinearity was less than 2 x 10(-4) forphotocurrents up to 200 muA. The diameter of themeasurement beam was found to have an effect on thenonlinearity. The measured nonlinearity of the trap detectorsdepends on the polarization state of the incident beam. Theresponsivity of the photodetectors consisting of the large-areaphotodiodes reached saturation at higher photocurrent values comparedwith the devices based on the photodiodes with smaller activearea.
TL;DR: The performance of a photodetector fabricated using a standard CMOS process on SOI substrate has been studied in this article, where the authors show that the depletion region induced by the floating gate separates the optically generated electron-hole pairs in the direction perpendicular to the current.
Abstract: The performance of a photodetector fabricated using a standard CMOS process on SOI substrate has been studied. The photodetector is basically a floating gate SOI NMOSFET operating in the lateral bipolar mode. The depletion region induced by the floating gate separates the optically generated electron-hole pairs in the direction perpendicular to the current. This results in an extra current amplification beyond that of a normal lateral bipolar transistor. A high responsivity of 289 A/W has been measured with an operating voltage as low as 0.1 V. The impacts of technology scaling on the performance of the photodetector are also studied.
TL;DR: UMSM-PDs with a 70 nm i-a-Si:H overlayer, 1.45 /spl mu/m-deep recessed electrodes, and 3 /splmu/m finger width and spacing, had a responsivity of 0.25 A/W as measured with an 0.83-/spl µ/m incident semiconductor laser, and an internal quantum efficiency of 36%.
Abstract: U-grooved metal-semiconductor-metal photodetectors (UMSM-PD's) having various trench depths of interdigitated electrodes and an intrinsic hydrogenated amorphous silicon (i-a-Si:H) to c-Si heterojunction have been fabricated successfully on a p-type [100] Si wafer. The U-grooved structures on c-Si were achieved with a simple orientation-dependent etching (ODE) process. Some important characteristics of the obtained UMSM-PDs are presented and discussed. An UMSM-PD with a 70 nm i-a-Si:H overlayer, 1.45 /spl mu/m-deep recessed electrodes, and 3 /spl mu/m finger width and spacing, had a full width at half maximum (FWHM) of 50.6 ps and a full-time of 132 ps for its temporal response under a bias of 15 V. The significant improvements of transient response for UMSM-PD, as compared to the conventional one, were attributed to the trench electrodes resulted in a stronger lateral electric field in the light absorption region of photodetector. At a bias of 20 V, this UMSM-PD had a responsivity of 0.25 A/W as measured with an 0.83-/spl mu/m incident semiconductor laser, a high photo/dark current ratio about 2000, and an internal quantum efficiency of 36%. This high photo/dark current ratio would be due to the additional i-a-Si:H overlayer on Si wafer. These mentioned performances were much better than those of the conventional Si-based planar MSM-PD.
TL;DR: In this article, a new thermopile structure using n-poly/p + -active layers that are available in any CMOS technology is reported. But the n-well regions are removed using a short EDP etching to reduce the thermal conductivity of the suspended structures, improving the responsivity significantly.
Abstract: This paper reports a new thermopile structure using n-poly/p + -active layers that are available in any CMOS technology. The thermopile structures are obtained by post-etching of the fabricated and bonded chips. P + -active layers are placed in n-well regions. which are protected from etching by the electrochemical etch-stop technique in a TMAH solution. The n-well regions are then removed using a short EDP etching to reduce the thermal conductivity of the suspended structures, improving the responsivity significantly. The characterization results show that Seebeck coefficients of the n-poly and p + -active layers are - 320 ± 15 and 430 ± 20 μV K -1 , respectively, resulting in a total Seebeck coefficient of 750 ± 35 μV K -1 . A two-arm bridge thermopile test structure results in a responsivity and a detectivity of 49.8 V W ' and 5.75 X 10 6 cm Hz 1/2 W -1 , respectively, in vacuum when the n-well is removed.
TL;DR: Using GaN Schottky diodes, the fabrication of a complete solar-UV detection head that uses GaN-based photodetectors and preliminary data on Al(x)Ga(1-x)N (x = 0.15, 0.22) detectors are presented.
Abstract: We report on the fabrication of a solar-UV monitoring system that uses GaN-based photodetectors. GaN photoconductors, p– n junction photodiodes, and Schottky barrier photodiodes have been fabricated and characterized as UV sensors. The best performances are obtained in Schottky photodiodes, which show a linear response, a flat responsivity of 100 mA/W, a visible rejection ratio higher than 103, and a noise-equivalent power of 1 nW/Hz-1/2. Preliminary data on AlxGa1-xN (x = 0.15, 0.22) detectors are also presented. Using GaN Schottky diodes, we fabricate and evaluate a complete solar-UV detection head.
TL;DR: In this article, the photocurrent transient characteristics of an AlGaN/GaN heterostructure UV detector have been studied and the observed PC transient characteristics are directly correlated with the effect of persistent photoconductivity in the two-dimensional electron gas region caused by deep level impurities.
Abstract: Photocurrent (PC) transient characteristics of an AlGaN/GaN heterostructure UV detector have been studied. We observed that the PC transients of the AlGaN/GaN heterostructure depended strongly on its initial conditions. Under a pulsed laser excitation, the PC responsivity, dark current level, and decay time constant all increased progressively with the number of successive excitation pulses and eventually saturated at constant values after about 30 pulsed laser exposures. Our results indicate that the observed PC transient characteristics are directly correlated with the effect of persistent photoconductivity in the two-dimensional electron gas region caused by deep level impurities and can have a significant influence on the performance of the UV photodetectors based on AlGaN/GaN heterostructures.
TL;DR: In this article, a 48 μm cutoff wavelength (λc) Si far-infrared (FIR) detector is demonstrated, which shows high responsivity over a wide wavelength range with a peak responsivity of 12.3±0.1 A/W at 27.5 μm and detectivity D* of 6.6×1010 cmHz/W.
Abstract: A 48 μm cutoff wavelength (λc) Si far-infrared (FIR) detector is demonstrated. Internal photoemission over a Si interfacial work-function of a homojunction consisting of molecular beam epitaxy grown multilayers (p+ emitter layers and intrinsic layers) is employed. The detector shows high responsivity over a wide wavelength range with a peak responsivity of 12.3±0.1 A/W at 27.5 μm and detectivity D* of 6.6×1010 cmHz/W. The λc and bias dependent quantum efficiency agree well with theory. Based on the experimental results and the model, Si FIR detectors (40–200 μm) with high performance and tailorable λcs can be realized using higher emitter layer doping concentrations.
TL;DR: In this article, the authors report GaN pin photodetectors with very low dark currents (<10 pA at -10 V) and high external quantum efficiencies (/spl sim/35%).
Abstract: The authors report GaN pin photodetectors with very low dark currents (<10 pA at -10 V) and high external quantum efficiencies (/spl sim/35%). These photodetectors have a flat responsivity above the bandgap (measured at /spl sim/0.10 A/W) with a sharp solar-blind cutoff at the band edge.
TL;DR: In this article, a Fourier transform spectroscopy (FTS) was used to study the UV stability of silicon photodiodes in detail, and results were presented for different types of silicon (Hamamatsu S1337 and S5227 diodes, a novel PtSi-n-Si Schottky photodiode, and UVG and AXUV photododes from International Radiation Detectors).
Abstract: The ultraviolet (UV) instability of silicon photodiodes is a very complex phenomenon. The change in spectral responsivity after UV exposure can depend on the level of irradiance and total radiant exposure, duration of exposure, wavelength of the UV radiation, the type of photodiode, and the way the photodiode was stored and used before UV exposure. For a systematic investigation, the responsivity change must be determined not only at the wavelength of UV exposure but throughout the whole spectral range in which the photodiode is used. Obviously, a fast method is needed to perform corresponding measurements over a wide range of parameters. Therefore a new, fast and accurate technique based on Fourier-transform spectroscopy was used to study the UV stability of silicon photodiodes in detail. Results are presented for different types of silicon photodiodes (Hamamatsu S1337 and S5227 diodes, a novel PtSi-n-Si Schottky photodiode, and UVG and AXUV photodiodes from International Radiation Detectors).
Patent•
04 Nov 1998
TL;DR: In this paper, an array of 63 micromachined thermopile infrared detectors on silicon substrates has been constructed and tested, each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi--Te and Bi--Sb--Te thermoelectric elements films.
Abstract: Linear arrays with up to 63 micromachined thermopile infrared detectors on silicon substrates have been constructed and tested. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi--Te and Bi--Sb--Te thermoelectric elements films. At room temperature and under vacuum these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4×10 9 cmHz 1/2 /W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source. The only measured source of noise above 20 mHz is Johnson noise from the detector resistance. These results represent the best performance reported to date for an array of thermopile detectors. The arrays are well suited for uncooled dispersive point spectrometers. In another embodiment, also with Bi--Te and Bi--Sb--Te thermoelectric materials on micromachined silicon nitride membranes, detector arrays have been produced with D* values as high as 2.2×10 9 cmHz 1/2 /W for 83 ms response times.
TL;DR: In this article, a dc-coupled in-line optical detector based on a multisection semiconductor optical amplifier (SOA) is presented. But the performance of the two-section and three-section SOA is different.
Abstract: We present in this paper a dc-coupled in-line optical detector based on a multisection semiconductor optical amplifier (SOA). The key principle is to use a voltage reference correlated with the bias voltage level by the way of a two-section or a three-section SOA. So, by means of the differential detection, the signal dc-component is kept with reduced sensitivity to temperature and bias current fluctuations. Experimental and theoretical results are presented when a two-section SOA is used and performance predictions when a three-section is employed. The obtained responsivity is -63 VNV at 40 mA and over -110 VNV at 50 mA when the input optical power, measured within the fiber, is -13 dBm. When the SOA is biased at 40 mA, the detection bandwidth is over 1 GHz when the input optical power is -4 dBm.