I introduce the coherent ultrashort light pulse CDMA communication systems proposed by Salehi et al. in 1990 [1]. I also review some research progresses of this system [2--4]. 

[1]Coherent ultrashort light pulse code-division multiple access communication systems 
Salehi, J.A.; Weiner, A.M.; Heritage, J.P.; 
Lightwave Technology, Journal of 
Volume 8,  Issue 3,  March 1990 Page(s):478 - 491  
Digital Object Identifier 10.1109/50.50743 

[2]IEICE, Vol.E89-A No.11  pp.3018-3025 
 PAPER   
Improvement of Coherent Ultrashort Light Pulse CDMA Communication Systems with Distinct 4-Level m-Sequences 
Yasutaka IGARASHI, Ippei OKAJIMA, Hiroyuki YASHIMA, 

[3]IEICE, Vol.E89-B No.4  pp.1205-1213 
 PAPER  Fiber-Optic Transmission for Communications 
Performance Analysis of Coherent Ultrashort Light Pulse CDMA Communication Systems with Nonlinear Optical Thresholder 
Yasutaka IGARASHI, Hiroyuki YASHIMA, 

[4]IEICE, Vol.E85-B No.12  pp.2776-2784 
 PAPER  Fiber-Optic Transmission 
Dispersion Compensation for Ultrashort Light Pulse CDMA Communication Systems 
Yasutaka IGARASHI, Hiroyuki YASHIMA,